But you can do 1. I've done it several times with a 28' tag, haven't in my class A DP yet but it will just be slow, and a bit tiring at times because you have to concentrate on driving vs looking at stuff. The area up around Pt Reyes is pretty twisty, and I'd skip the golden gate and go east around the bay area and pick up 1 south of SFO somewhere. The traffic downtown after the bridge is a PITA - more harrowing than the coast!
I'm surprised more people don't use google earth as a resource. Just zoom in and drive all the way from point a to point b and use street view when you want a roads-eye view.