We were at the Napa Embassy Suites for the 4th fo July weekend, though it was expensive (though not so bad since part of our stay was on an award), it was a very nice hotel. One of the better embassies we stayed at.

For that region, if you are going winery hopping pick the ones you really want to see (highly recomended, favorite wines, etc) and make sure to do those first. if you start stopping at each one, the days will be gone before you know it.