@John Welte, The humidity content is horrendous here in the winter we had so many days this year with greater than 90% humidity.
We have a 3 sided metal RV port with tarps for the doors, so direct rain/snow is not on the Oli. We also can keep the Oli plugged in full time. The outside of the Oli itself during the winter along with the cement floor and the inside walls of the port would get dripping wet with moisture from the humidity. The first couple of years I opened the bathroom vent, and then turn the Maxair fan on it's lowest setting and l had the blinds completely open leaving the fan run all winter. I learned from winter camping out here if we did have constant air flow the insides of the trailer would be wet.
This last year, I was so busy working on the inside of the trailer, that I left a little electric heater set to around 55 degrees in the Oli and lock the Oli up tight, with all the vents closed. This year worked much better at lowering the humidity level in the trailer, although the electric bills were higher.