November might be my last choice, too much rain and very short days. If you choose fall go as early as possible and be finished by November. Short days means so many hours in the dark, later start times in the morning and dark early in the afternoon. If you'll be camping that means way too much tent time, and if it rains it will be that much more time under shelter. I can tell you that in the Pacific Northwest you are not just looking at rain showers in November, it rains for weeks with few breaks.