I’ll call it 2 full days. It’s one free day and two afternoons. This may not be descriptive at all but I’m more into historical/aged buildings and/or outdoor stuff over new/modern places. I don’t care much for wine itself but vineyard is a must try I suppose.
These recs are very much indexed to old/interesting places.
For your full day, consider venturing out a little farther north into Napa Valley and working you way back:
-Castello di Amaroso
-Cheateau Montelena
-Beringer
-V. Sattui (also picnic grounds)
-Oakville Grocery (not a winery, old cool spot)
-Walk around, get food in Yountville (also home of the French Laundry)
For your shorter days, Sonoma has some good closer spots:
-Gundlach Bundschu
-Buena Vista
-Bartholomew
-Go to Sonoma Plaza, walk around, enjoy some good food, reservations recommended
You’ll want reservations for tasting in general as well. I generally prefer the Sonoma vibes, but there’s cool stuff and great food & wine everywhere. Enjoy the trip!
Don’t over-extend yourself. Give lots of time for a tasting and travel time between. Max 3 on your full day.