I have concerns about holding moisture in by using a cover. However our solution to winter storage is to pack up and head south for the winter. Otherwise our Uhaul
would either be in our barn, or in the back yard where I could keep snow cleared off, check the interior occasionally, and monitor for rodent invasion and leaks
. Since I started using a mouse repellant inside the three campers I have stored inside, and poison underneath, I have had no more mouse problems.