I personally dont like rv covers because it will rub the corners of the Rv and they are a pain to put on. Find a good wax and use that. 

Tell us how your trip went in your Rented RV from Utah Trailer Rentals? 
Where did you go?
Did you have fun?
Will you go again?

You can either blow out your system thru the city water line or run RV antifreeze. 
I will always blow out the lines.
1.Drain your water heater
2.Pull your low point drains
3.Hook a air hose to your city water input
4.Open all your faucets (Bathroom, Tub, Outside Shower and Toilet
5.Your done!