I am going to throw in a vote for going to Sonoma, Mendecino County and/or/instead of Napa. They make some really good wines in both of those. It seems the further you get from Napa County, the less expensive tasting and wines become and the wine is just as good.
My wife and I like the spicy, peppery tastes you get as you go north. Two of my favorites are Selby Winery with a tasting room in Healdsburg CA (and there are several others in the same town that are very good) and further north up in Hopland you get Brutocao Cellars, they both have a wonderful Zin from the Russian River Valley AVA. Brutocao also makes a really good Port and a great Uber Tuscan. Also, try the Coro Mendicino at any of the northern wineries. They make it like a Chianti, in that most every winery makes them, they are somewhat rigid in the blend and then they all get together and blind taste. You might end up rejecting yours.
And no, I don't have any monetary interest in any winery anywhere, just know what I like.
