If you're going to catch a flight, I'd recommend staying at a local hotel near the airport that has a shuttle service to drop you off. The risk in the headache pf going through Napa to SFO would be offset by spending the night at a local hotel.
I live about 25 miles from SFO (Bay Bridge dependent) and will frequently spend the night at an SFO airport with shuttle service if I have a weekday AM flight. Last Saturday early AM, I was in an airport lounge within 1:15 after getting out of bed (then showering, throwing stuff in my bag, ride to airport, TSA, etc.) M-F, I'd add at least an hour, and monitor the traffic, as there have been a few times over the years that I've had to go down to the San Mateo Bridge and around - adds about 20 miles, but occasionally, is the only way to make your flight.