My original thoughts were whether we'd physically make the connection and, having read all of your helpful posts for and against, I think I'm being a touch naïve about the potential weather complications at ASE and SFO!

Hence, to be on the safe side, we've flipped our trip around and will spend a couple of days in SF and Napa at the end of our trip, rather than the start.

Thanks again to all contributors for your help!