The Rutherford Grill is very good. I have a eaten there a couple of times. Always delicious.
The Coppola Winery is a blast but I hope you’re aware that about an hour’s drive from the Napa Valley or Glen Ellen. It’s a very pretty drive, though, especially this time of year! If you’re taking Hwy 128, be sure to stop at the Jimtown Store for food and souvenirs.
Thanks again for all the suggestions. We had a wonderful time.
On Saturday we started at the Sterling Winery, which was very impressive, with its aerial tram and extensive visitor center. We chose the “Sterling Silver” experience, which adds tastings of three wines and access to their art gallery to the standard package.
From there we went to St. Helena, where the plan was to have lunch at Giugni’s, based on the recommendations here and its high ratings on Yelp. But we didn’t realize that it was just a small market, with no public restrooms and limited seating. Both tables were taken, and one of our party needed the restroom, so we ended up at the Nepalese restaurant across the street. Although I had been looking forward to a sandwich from Giugni’s, our curry dishes were very good, and the naan was great.
Then we went up to the Coppola Winery. Although it also has an impressive facility, and it was interesting to see all the movie memorabilia, we were less impressed with the wines, and disappointed that there was no tour of the winemaking facilities, as there was at Sterling.
We had dinner at the Rutherford Grill and enjoyed it a very much.
Sunday we rode the Wine Train. The meal and service were excellent. (My pork arrived a little cool, and they immediately got me a fresh, and hotter, dish.) The ride is slow, but through beautiful countryside. The restored rail cars are beautiful. Everyone had a lovely time.
Afterward, we stopped in at the Oxbow Market, then wandered around the streets of Napa for a little while before heading back to our Airbnb house in Glen Ellen. We had dinner at the Glen Ellen Inn, also very nice.
In short we had a great time, and I’m sure we’d all love to come back and spend more time in the valley. Thanks again to everyone here for your help.
If you plan another trip, especially if it’s in the summer, consider Carmel Valley instead. It has great wine, lots of other things to do, and will let you experience what Napa was 40 or 50 years ago. 
Not that Napa is bad-- it isn’t. It’s fantastic. It’s just that CA has many wine regions and Napa is just one.