I don't know about covering it (unless under a roof or in a building) with an RV cover. RV covers keep an RV too closed up. We had a nasty mold problem once that developed inside an RV we kept completely closed up during the winter.
I'd recommended not covering it and keeping a front roof vent and a rear roof about half-way open (assuming you have rooftop covers over the vents) for good fresh air cirulation. Also, keep a thermostatically controlled electric heater inside turned to 50-55 degress so as to further keep moisture driven out and everything dry. It's the UV rays from the hot spring/summer/fall sun that can ruin RV exteriors more so than anything else ... so keep it covered those times of the year (under trees or a roof structure) ... but STILL with some interior air circulation. I'd never use an RV cover on ours, anytime, because fresh air circulation is impossible then.
Mold/mildew inside an RV can get into "everything" and come close to ruining it for human occupation from then on. We never want to risk this happening again!
