PNW
Snicker snicker. Welcome to the PNW. Where from?
I'm a native sailor of the PNW and can say with a straight face that our weather has had no measurable affect on our dodger and bimini over the years. During these colder and wetter months the canvas will accumulate green stuff, which will wash off with soap and water with a light brush scrubbing on the cloth parts only. I use a plastic cleaner and polisher on all the clear plastic parts.
Prevailing winter winds usually come out of the south, so to help reduce pressure on your canvas orient your boat's bow towards the south if you can. If not, no worries. We keep our boat ready to go year around taking advantage of weather windows to enjoy winter on the water. Most all canvas made dodgers including bimini can withstand PNW winds; ours has and it was made in 1991, albeit a bit weathered but still serviceable.
One other consideration is your head sail. I leave our sails and sheets on during the winter for the above reason. I will normally take at least two sheet wraps around the furled sail just to make sure the wind will not force it to unfurl.
If you are that concerned about your boat you can always remove all that stuff and store it for the winter, place extra fenders to protect the boat and winterize. What works for us is to keep three small dehumidifiers running (one in each cabin) and a space heater set on low to ward off mold.
Hope to see you on the water. Our boat is Belle-Vie, a 1991 Hunter Passage 42 center cockpit.
Terry Cox