We stored our motorhome the 1st winter in MI - outdoors, uncovered. We did not put the jacks down as we were parked on grass. Slides were in. We scattered Bounce fabric fastener sheets throughout, in drawers,behind sofa, etc. We did not have any mice and were parked by a field in the country.
We left the house and engine batteries in, shut of the battery switches. When spring came, we turned engine battery on and it started right up. One thing we would do differently ---- we would remove the batteries , both house and engine and store them indoors ( our house battery did freeze). We also put Stabil in the fuel systems and ran the generator to get it thru that fuel system before storing. We did not run the engine or the generator during the time it was stored. We started full-timing after that, so never stored it again.