Some really good info here, thanks everyone.
In terms of housing, we wouldn't purchase anything until we tried this out for at least a year and know it's workable/desirable, but eventually it would be nice to get a single family home for under $1M. We've been renters for life so far. Starting to wonder if that's just a pipe dream at this point with the housing market the way it is, but we'll see! What goes up must come down right?
I personally like "Superior California", i. e. the northern part starting from around a line connecting Monterey-Fresno-Lone Pine to a line connection Reno- Fort Bragg. I was born in the central valley so I may be biased as a native. Moved away when I was 10 but I have traveled back many times, probably at least 25 times since 1988, possibly many more.
If your SO needs to be "near a major market" I'm not sure what that means and I would not pry. But if I were nearing retirement and just had to stick it out a few years I would consider living in "Gold Country" which is generally along state highway 49 (remember the 49ers and I'm not talking football) from Placerville to Auburn. You will be a few hours from SF but a much calmer and more peaceful lifestyle at MUCH cheaper property prices. It might be a 3-hour drive into town (or possibly a short commuter flight) but if he/she could do it once a week and back and spend a couple of nights in a hotel it might be doable.
Again, not sure of the nature of your SO's work but remote work is common in the Bay Area and was before Covid, depending on many factors of course. I personally know a couple of people working full time remote at Bay Area jobs, one living in Mt. Shasta and the other in Hawaii. Oh, and forgot about my neighbor who is a project manager for Google. The point is, you might find Bay Area companies that are not owned by Elon Musk to be very open minded regarding work relationships.
Beyond work, the Bay Area offers a lot of cultural, sports, and other entertainment options. Living in a place like Auburn puts you 3 hours from the SF Ballet but is that a serious problem? You'd only go about 6 times a year even if a super fan. Maybe you cant afford to make every Giants or 49ers game though. I speak from experience...I live in Hawaii and have commuted by plane for both the SF Ballet as well as 49ers and Golden State Warriors games!
Of course NY offers similar, possibly better entertainment opportunities. My only point is that I really love the SF area and living even 3-4 hours away in retirement would be awesome.