I would probably leave no later than 7:00.

I only park at the airport for very short term, but if you go into the terminal lot, head all the way around to terminal 3/United and try to park by the elevator.

I use ParkSFO for parking, but you have to leave probably another 20 minutes for parking, shuttle, ect.. Look up coupons on line, as I find with the coupon it is the cheapest and for me most convenient.

The other option is to take the airport express bus from STS airport in Santa Rosa.

It really is an easy ride, but the traffic can be very unpredictable.