AFAIK, once you get to SF, Highway 1 ends, From there on it's US 101 up the coast. Certainly in Oregon it's an easy drive most of the time. We've done Astoria to Brookings a couple of times. We haven't ventured into CA very far. If you're doing it in late fall, be aware that fall is when Cal DOH gets into its highway maintenance program and there can be dozens of one-way traffic zones.
The biggest problem last time was that the fridge died the day before we left. We must have visited every Fred Meyer store on the coast, buying ice!
Frank and Eileen
No longer RVers or FR owners