@jbomforman early November backpacking in WA can be amazing, but specific destinations may be more/less feasible depending on how early winter decides to arrive. Freezing levels can drop quickly, and if there's any early snowfall, you may need to reconsider previously open destinations. One of the best resources for hiking/backpacking in WA state is the WTA.org, where you can search for specific hikes or general suggestions, like "November backpacking."
Hope this helps as a starting point, and then ideally you'll get some specific suggestions from other members of our community! @REI-AlexxD, @REI-BarryP @REI-DaveK @REI-TaylorH - any recommendations?!