Wine Country north of San Francisco

Just don't do what we did -- we toured the Dry Creek area near Healdsburg on bikes. Wine tasting and hilly terrain do not mix. (Great Zinfandels, though.)

I grew up in the Sonoma Valley and my wife and I lived in Napa Valley for 12 years. She worked at 3 Napa Valley wineries as a wine educator.
Napa Valley can be overpriced but the Valley is gorgeous, especially in the spring.
A lot depends on your level of wine experience and tastes. In Napa Valley, We recommend Castello d' Amorosa, Sterling, V. Sattui, Rombauer, Chateau Montelena, Hagafen and Darioush. Most of these are recommended for the experience, as well as good wine.

Some many Dry Creek area. Some better ones - Rodney Strong, Rafaneli, Esterlina, Forchini.

Not sure about any campgrounds existing in Sebastopol, however Rivers End campground in Forestville can handle your rig and Is 3 miles +/- to Korbel winery. Westside Road is also very close offering some of the best Pinot and Chardonay around rivaling Oregon and the central coast. Campground can be busy during the summer and harvest is in full swing now.

Get into a nice campground in Sebastopol, it's the nicest city out there, and sign up on a 4 to 5 star wine tasting tour.

Then when sober, take your own road trip to the area. It's beautiful with charming downtown in their cities.

Yup, can be crowded on weekends.

It's not all doom & gloom like older_fossil implies. And yes, I prefer the Paso Robles wineries, but that's just because I went to university there and it's sentimental. I have tons of great childhood memories from the Napa Valley as a kid too when my broke parents would drag us around wine tasting. It used to be free back then, so it was a great way to learn what you like. It was free too when my then-girlfriend-now-wife would go tasting in Paso Robles when we were students, which is how we learned what we liked.

There's absolutely nothing wrong with the Napa & Sonoma valleys, and the crowds shouldn't be that big of a deal. The cost for tasting can be high some places, but not prohibitive and you're on vacation so live a little.

Just be prepared for crowds and high prices. If it were us, for wine we'd rather spend time in the Paso Robles area in mid state or further south in the Santa Ynez Valley.

Art