I think I would like one the 20 ft models. It would be a dwelling that is used only on weekend retreats. I dont think I would leave it up in the winter because of snow load and not being up there to keep the snow off of it. Could it be set up as a getaway shelter that I could have lets say a bed and sofa set up in and feel safe the water and mildew will stay out.
Yes, the structure is rain proof. If it gets sun, the sun will drive out the dampness and help control mildew. Heat is needed to dry the air every so often or else mildew can develop.
Anything else that I should have with it that would help me with my needs.
You will want to have a water proof floor to keep the dampness of the ground from entering your space.