Class A skirt for winter storage

The skirt and electric heater would probably work. It would be inside a garage so the wind wouldn't rip it apart.

But, I agree with the others. Take the time to blow out the lines and pour antifreeze in the traps & toilet.
Then you don't have to wonder if it gets too cold or the electricity and or heater failed.

I would rather winterize. What happens if power goes out while you are out of town?
Or a real good cold snap for a week.
Foolish not to winterize and be sure.
If you do not like antifreeze then blow the lines out well with air and drain the holding tanks.

very $$$$

Blow out the pressure lines and a cup of the red in the p-traps. Less than $10 and 30 minutes.