Thank you all for your very informative comments.

After taking everything into consideration plus other searches for information, we decided to modify our itinerary slightly.

Fly into San Francisco and pick up a car.
Drive to Sonoma for 1 night and drive back to SFO and stay 4 nights. We would then drive to the Monterey Peninsula and stay for 1 night and a stay in San Simeon/Cambria for two nights. The rest of our trip will stay the same.

We would appreciate hotel accomodation suggestions for Sonoma, Monterey Peninsula and near the Hearst Castle.

Thanks.

Hi jet29, when you say you will stay four nights in SFO are you talking about hotels at/near the San Francisco airport? I hope not. SFO is the code for the San Francisco airport.

San Francisco is SF. I hope that is what you meant..that you will stay in SF? Best wishes to you, and welcome to California.

yes, we will be staying in San Francisco (not SFO)