My two cents worth, if you must live in the Pacific Northwest, especially in winter, is buy a proper dehumidifier, one which uses a refrigerated coil to condense water out of the air, and use it. Anything short of this is unlikely to keep up with even one person in a small trailer. Powering a dehumidifier with solar or wind would be a challenge, the power use is relatively high. Think small electric refrigerator, that is pretty much what you will be feeding.
Even with a dehumidifier, you will have to be careful about condensation in cupboards or behind cushions against outside walls. Ventilation is your friend.
Dehumidifiers are among the least reliable household appliances out there, so warranty coverage is worth making a priority.
OTOH, if you don't have to live in the Pacific Northwest in your trailer in the winter, there are other places which are warmer and drier...