Magilla.....Years ago I bought a very expensive Adco cover, made from the heavy storage cloth they use on boats. Back then, my 37' cover cost $1200.00. It was very heavy, but I devised a system to get it easily on the roof. After covering the coach after each trip, the first year, we found it to be a pain. We live in Southern California and the coach goes out almost monthly. I boxed up the cover and it sits in storage.
With that said, if had to park and winterize my coach every year, I would definitely buy a heavy cover like the one I bought and cover the coach. I'm not sure if they even make the heavy duty ones anymore.
If you can't get it under cover, I would at least buy one of the $300.00 Adco covers, use it for the winter and toss it at the end of the season. To me the $300.00 would be cheap insurance.