Your description definitely sounds like the Ford Flex. It’s the nearest thing made to an old-fashioned big station wagon, though it sits up slightly higher. Most of the biggish crossovers come with some form of panoramic sunroof, only a part of which opens. The only true crossover convertible of recent years is the nutty Nissan Murano CrossCabriolet. It’s a true convertible version of a mid-sized crossover and looks very odd. However, it only has two rows of seats and only seats four comfortably. It looks like a giant baby buggy to me, or some kind of toy.
The Flex is the most like a wagon, but other good three-row crossovers include the Honda Pilot, Toyota Highlander, and Mazda CX-9. I especially like the Mazda. In all cases the third row is best for kids, but large enough for smaller adults as long as they can climb back there (so not for the very elderly, probably.) All of these are available in bith fwd and awd versions and are perfectly suitable for winter driving on normal roads.
Tires will be a bit tricky, living in the Bay Area, with our mild winters. Most people recommend winter tires for driving in ice and snow in cold climates, like your ski trips, but winter tires are only meant for places where the temperatures average below 40 degrees. In Bay Area winter temperatures they would be terrible to drive on and would wear out in no time. You could just stick with normal all-season tires, which is what you’ll want to be using except on the ski trips, or you could use so-called mud&snow tires. They have different tread than all season tires and would be better up in the mountains, where much of your driving figures to be over 40 degrees anyhow (during the day). They don’t use the same rubber composition as winter tires, so don’t wear out as fast. They’d be perfectly suitable for our somewhat rainy winters, if noisier than all-season tires You might want to have two pairs of wheels so you can easily switch to the mud&snow tires in the late fall and back again in the spring.
Your story sounds like my partner’s, Miranda. He also spent 13 years in Europe (Cote d’ Azur) and moved to San Francisco on returning. But that was 20 years ago. Took some time to adjust since he had left from Boston.