This is a good question!! And Larry, thanks for your input.
Just thought I'd throw this information in just in case some of you may want to consider this option. If the water heater in your RV is strictly gas operated, Camping World sells a conversion kit to change it to electic. My DH did this to our 2002 Dutch Star & it worked like a champ. Why use your propane when you can use Disney's electricity! I don't remember what it cost, but CW has a website you can check.