Winter is usually a very clean time of year. Winter on the roads is filthy, but leaving something covered in clean snow isn't an issue. No pollen, usually very little dust. Not much to worry about on the tongue. WD on the coupler and 303 or other uv protectant on the tank cover (and battery box if you don't remove that with the battery). Not sure what kind of "work" you're avoiding by covering it.
'01 Burb 2500 4x4 496/4.10 (3.73 effective w/ new tires)
'94 Jayco 300BH