Unless you really have your heart set on it, I’d drop the Winchester Mystery House from your itinerary. It’s pretty much a hokey tourist trap. Seriously I’d recommend Hakone Gardens (again) in Saratoga instead-- just a hop skip and a jump from Montalvo. It does have historical and cultural significance, and is just a beautiful, restful spot.
It will be over two days, staying over someplace on the coast. The first route you suggested sounds perfect, thanks!
wevets, I wanted to go to Point Reyes but we just won’t have time. It looks like e’ll be going right through Trinidad, though, so I’ve put it down as a good coffee or meal stop. 
John Mace, I really do appreciate your input. I’ll take your advice and skip Winchester House. With my mom not being so mobile I’m not sure about Hakone Gardens. She’s ok with walking a little bit, then sitting and looking at the scenery, then walking a little more (while I go off to see all I can). It sounds like this would be a good place for my mom to do this, what do you think? Or is it more like you get on a path and then are committed to a longer walk?
Hakone Gardens should be fine for your mom. There is a loop around the gardens that involves a steep climb, but if she just wants to walk a little and then sit and look and the gardens and koi pond, the paths for that are not taxing. My dad has trouble with steps but he was able to manage.
We leave on Tuesday. I have all the reservations made and an itinerary set up. I usually like to be a little more free-wheeling, but I have time limits so we’re pretty (ambitiously!) scheduled. Included are San Jose area, Napa, Clearlake, Humboldt State Park, Mendocino, up to Crescent City, exciting Grants Pass :D, Crater Lake, and Bend.
I also have to spend a little time in Hillsborough to visit the graves of my Godmother and her husband who both died unexpectedly last year. Before that happened, most of the trip would’ve been spent with them. So it will all be a little bittersweet, hanging out in their area without them, but they’d be glad to know we were spending time there.
If any of you in this thread would like a postcard during our trip as a thank you, please PM me a mailing address. 
Pretty sure I’ll miss the edit window so I’m just going to add another post. JohnMace, I’ll be spending probably seven or eight hours at Villa Montalvo. The sound check is at 3:30, then we’re having a fancy dinner there at about 5:30, and then the concert. I wonder if they’ll keep us corralled at the venue or I’ll be able to walk around. I do plan to get plenty of pictures as it looks spectacular on the website.
Have fun!
On this leg I assume you’ll be on U.S. 101 northbound. When you get to the State Highway 36 interchange near Fortuna wave at me off to the right. My place is visible from that interchange.
And remember, L’s Kitchen in Fortuna for breakfast (closed Mondays) if the timing is right.
Finally, as Robert Prosky, a.k.a. Sgt. Stan Jablonski used to say in Hill Street Blues, “Let’s be careful out there.”
From 101 you can detour briefly to the wayside with the elk herd at Reedsport.
Wish I could help, but I’m not sure. Often, they have parking offsite and shuttle people to the venue, so you may be at their mercy (although I guess there is always uber). Still, I could think of worse places to spend 7 or 8 hours!!
ETA: I’m pretty sure you can walk around the site, for sure, if that is your concern. Getting offsite might be problematic.
ETAA: It’s been really cool lately, but the forecast is for very warm weather this coming week. 80s - 90s.
I’ll be very happy just to be able walk around the place! 
Thanks, everyone! Will let you know how it all goes! It will be a lot of driving but I’m pretty excited.
The Crazy Norwegian in Port Orford, Oregon is the best fish and chips I’ve ever had.
Portola Redwoods State Park and Crater Lake are both very beautiful and were the highlight of our roadtrip.
Have fun!
I like Redfish in Port Orford, too.
I just drove by Villa Montalvo on my way home, and I was thinking about this thread. Let us know how the trip went and how the concert was!
It went mostly well, and a few highlights were because of suggestions made by you folks! Driving down I expected I-5 to be boring, but we spent some time stopping to take pictures of Mount Shasta and Black Butte. That was an unexpected pleasure.
Villa Montalvo was stunning and the food was excellent. It’s the most beautiful venue at which I’ve ever attended a concert. When we were driving there, it was an area of such lovely homes it was difficult to conceive there was a concert venue at the top. I love wood so I spent a lot of time gawking at the floors, walls, and lovely woodwork of the main building. The soundcheck and concert were wonderful, and I got to meet the band! It was a great time. We paid $30 for on-site parking and I’m glad we did because the lines for shuttles were miles long! I think they were coming from a nearby community college parking lot.
We ended up not having much time in the area so we didn’t make it to Hakone Gardens, sadly. We got there pretty late the day before the concert, and I was meeting my friends at 1:30 the day of, and we left early the next morning.
We drove through Napa and saw more area than we intended because I took a wrong turn. We did stop at Dean & Deluca for some food. We left Napa heading north and ran into the craziest hairpin turns I’ve ever encountered. They went on and on for miles. I started to feel sick and thought I got motion sick, but soon came to realize I had a case of food poisoning. We’d stopped in Hercules and had lunch at an Asian place. Let’s just say I had a really bad night.
But, although weak, I was ok the next day. The next few days were spent on Redwoods Highway/101. I did wave to you,** ASGuy**! I wondered which house was yours! Fortuna’s a nice little town and I wish we’d have had one more day there. We didn’t get to L’s Kitchen because we’d already eaten the motel breakfast, but we did drive by it.
As far as Redwoods go, Humboldt State Park was perfect. We did the 30-mile drive and even stopped and had a picnic under those spectacular giants. It had an educational visitors’ center.
I really can’t describe that whole experience of spending time with those trees. It was almost spiritual. Another wonderful experience was hiking down to the beach in Trinidad and being the only one there. Wow. Thank you, wevets. We probably wouldn’t have stopped, otherwise.
I wanted to stop to see the elk at Reedsport, but my mom didn’t, so we didn’t. She was a pretty good sport about everything I wanted to do so I let that one go.
It was a tourist trap, but I’d been to Trees of Mystery when I was a kid and distinctly remembered Paul Bunyan and Blue. I wanted to see them again. They’re in the parking lot so it’s not necessary to pay admission to see them, but we went in anyway as I wanted to walk on the trails and ride the Sky Train through the redwoods. My mom is afraid of heights, but she was very brave and went up, too. She loved it at the top. They actually do a nice job with that part and the trails, but they do get you in the souvenir shop! Holy crap! We got the same kind of stuff at the little places by the side of the road for a quarter of the price!
The last interesting stop was Crater Lake. I’m not a very good photographer, but it’s such a photogenic lake that I didn’t get a single bad shot of it. It was beautiful, but they’re doing construction and had completely destroyed the west rim road. It was gravel and one-way for quite a long way. It really marred the beauty of the day. I wish we’d taken the east rim road because it probably would’ve taken just as long.
I put over 2,000 miles on the car and have done enough mountain driving to last me a very long time, but it was a great trip. Thanks again for your wonderful suggestions. I hope we can go again in a few years and spend more time in the places we liked, and visit new ones.