I rode from Astoria to San Francisco last year in three weeks from the end of September to mid October. There really are no bad places to take a rest day. My only regret is not taking addtional time to ride the Lost Coast Loop. There are enough hill climbs thoughout the ACA route that I just took rest days when my body felt like it was needed. If you are camping, the Oregon State parks are excellent. If you are staying in hotels, then maybe you will want to stay an extra day in Seaside and Mendocino. The Avenue of the Giants is another great place to spend an extra day. There's no bad choice for that tour.