If you have full hook-ups at your campsite, then why bother de-winterizing? Just go to your site , hook-up and turn the water on and everything will go down the drain , making sure your water heater has not been by-passed, and if so then follow the directions in your instruction manual and make sure you have your anode rod in place and tightened and you should be ready to go.
If you do not have hook-ups then you will have to carry a lot of water depending on how long you will be there.
2007 Jayco Eagle 325BHS
2010 Dodge 3500 Laramie
Kipor 2000 Generator