That’s where I live, I didn’t even think to include it in “charming rural towns” but I guess it can be. I guess because where I live is suburban and technically “in” Columbus but 15-30 minutes away from the city, but I don’t live “in town.” There are many suburbs and certainly many rural areas (I’m never more than 5 minutes from farms and small towns) surrounding Columbus but I’m not sure about the “charming towns.” If the in-town area of the city of Pickerington qualifies then I imagine there are a few more. There are a lot of places within 30 minutes of Columbus, and while people don’t seem to mention it much there are definitely tech jobs and tech positions with the dominant industries like insurance and banking and a lot going on there. There are sports teams, theater, music, shopping/dining/bar districts, big university, etc. Someone who lives in LA or NYC might think it’s a boring non-major city but it’s a big city to me.
I think this may be a function of where you were in California rather than the state as a whole.
Rochester - Winter followed by spring - fall. No summer.
Cite: Lived in NY state; Albany area and Finger Lakes. Beautiful 6+ months of the year. Music, wine, universities.
I think your search should focus on University towns. Madison, WI Lansing, MI and the like. Lively, tech scene. Perhaps “smaller” but they have everything. Small towns right outside.
Pittsburg PA left steel behind years ago. Thriving tech area now. Rural towns outside may be a little stifling.
Chagrin Falls, Ohio - 25 miles from Cleveland.
Population: 4,000(ish)
Very cute place.
Knew a guy worked downtown Seattle, lived on an island (Vashon, I think). If traffic was bad and he just missed the ferry, he’d be home two hours late. His family learned not to wait dinner for him.
ETA: Looks like they’ve added rush hour ferries. Now he can be only 45 min later… but still enough of a delay that he’d be getting leftovers.
I lived in Madison, WI. Wonderful place, but the winters were long… and shitty indeed.
Boulder City is less than 30 minutes from Las Vegas.
If unincorporated communities count, then Las Vegas has many nearby including Corn Creek, Sloan, Blue Diamond, Mountain Springs, Goodsprings, Sandy Valley, Glendale, and Nelson.
Morgan Hill happens to be a town I know extremely well. It’s not terribly charming. 
This is one of those questions where the issue of “A million people” is kind of odd. Are we talking city or metro? City would exclude cities that are preposterous to exclude, like Boston (617,000) or Vegas (580,000) but “metropolitan” is often so preposterously widely defined that it encompasses anything you could drive to in thirty minutes.
The closest big city I live to, Toronto, has no small town you could drive to in thirty minutes from any point in the City of Toronto, simply because the surrounding metro area is densely populated for miles around. If you proceed west from the city border you start off in yet another city of 700,000, and best of luck getting through THAT in thirty minutes. If you do you are simply in yet another big city.
It seems likely to me that the only candidates would be towns outside of cities that are big but not TOO big - a million bang on. Ottawa is about a million people and you can get to some charming little towns in thirty minutes from the city border.
Go northeast out of Sacramento and you’ll find some very nice towns like Rocklin, Loomis, Lincoln, and Sheridan. Directly north you can find Yuba City, but that’s getting to be pretty big now. To the northwest are really nice little towns like Winters and Woodland.
In the Albany/Schenectady/Troy area there are several choices.
Altamont certainly fits the criteria. It’s less than 30 minutes for Schenectady, though maybe a little more from Albany.
Ballston Spa (Pop. 5500) might work. You can certainly get to Schenectady or Saratoga Springs in under half an hour. Possibly Troy and Albany, too, depending on the traffic.
From Troy, there’s Hoosick Falls (pop 3500). Bonus: There’s an amazing Revolutionary War battlefield (the Battle of Bennington was fought there). Downside: the water was contaminated by chemicals and I don’t think they’ve finished cleaning it up.
Alplaus might fit, though I’m not sure if it qualifies as a village. But Kurt Vonnegut lived there, so that’s a plus.
Delanson and Quaker Street are also with a half hour of Schenectady.
Hicksville’s not rural. It’s a suburb.
There’s several wonderful small towns outside Little Rock.
My favorite is Sheridan AR. 35 to 40 minutes away. Has a great school system. The highway dept recently completed a bypass that eliminated unnecessary highway traffic.
Jacksonville and Cabot AR are great towns. Jacksonville is 7 miles from Cabot. Both are 20 to 30 minutes away from Little Rock. My mom recently bought a retirement home in Jacksonville.
Traffic can be a problem for commuters. But that’s true anywhere.
The OP really needs to at least define where the 30 mins starts from.
All five cities mentioned above have charming rural towns within 30 minutes from their city centers, and definitely from their city limits, for certain values of charming.
Houston: Fulshear and Brookshire come to mine.
Dallas: Waxahachie, Ennis, Terrell
Fort Worth: Decatur, Weatherford, Cleburne
Austin: Dripping Springs, Johnson City, Lockhart, Bastrop,
San Antonio: Boerne, New Braunfels (although that’s stretching things some)
Washington has several charming rural towns within close driving distance, like Occoquan.
I haven’t been there for years, but Moorestown, NJ may fit the bill for you if you want to be near Philly. It’s not exactly a horse and buggy town, but I’m sure there is still farm or ranch property available. It’s also close to Haddonfield which is another fine town (with charming main-street shopping).