[Festus2]

I wouldn't shrink wrap it. For one thing, it would trap moisture inside resulting in mold - not a good thing - as well as promoting rot.

If you are concerned about mice or other similar critters, go around your unit and plug up all the openings and holes you can find. Remove all food and set out mice traps or bait in various places inside.

Putting an RV cover on it won't deter or prevent critters from trying to get in.