I forgot to mention that we will be staying in a B&B in Oakville. Don't know if that makes any difference since everything looks fairly close together.

Oakville is very centrally loc'd in the Napa Valley so you should be fine regardless of your itinerary. I would suggest doing one tour per day plus visiting 2 or 3 additional wineries for tasting only. You could always do a reserve or library tasting which is usually a sit-down affair with personal service and a limited number of participants. I'm not a great fan of Pinot Gris or Grigio, but Robert Mondavi Winery has a large varietal selection and may be one place to check. Pinot Gris/Grigio is a nice summer wine, but still not hugely popular so many of the wineries that produce it might not offer it as a tasting option--you will have to inquire. Also be sure to check with your innkeeper as they can make suggestions given your group's wine preferences.

My suggestion is to do 2 tours a day allowing generous time for a nice relaxing gourmet lunch in between (e.g. CIA Greystone). If you have time leftover, you can always stop by some of the smaller wineries for tasting. Yes, the area is fairly small and seems close to everything but the traffic can be a nightmare on weekends with bumper to bumper at snail pace. If you have time, stop in at the COPIA first and take a tour there and take advantage of the coupon book they have since it has numerous discounts from most wineries in there.

Once you decide which tours to take, you may want to reserve in advance since many of the guided tours limit that to a small group like 10 or 12 people and certain time of the day especially their "deluxe" tours.

For dinners, there are plenty good restaurants to choose from but reserve in advance particularly the popular ones. Most require credit card to hold. Have fun.