It depends if and how much you'll be drinking. I refused to pay Mr. Keller and company 4x retail on the "lower end" stuff (and overall, ridikyoulus markups on the entire list when I visited) so we had delicious water, the perfect pairing for all those disjointed courses, and drove home. And this was during the bargain days of TFL, where the two of us got out of there for just north of $600 without beverages.

You're either driving or you're not. So, the 10 minute drive to a nearby town is just as bad as an hour-plus drive. Unless you're staying in Yountville, check to see how available rideshares and taxis may be around the time of your dinner needs.