Re: Most efficient way?
Andy,
If no hookups exist keep hot water heater off until 1/2 hour before your shower, dishwashing, etc. then turn off again.
I do this and can stretch 20 gals of propane, for a month +.
Hopefully, you'll have a hookup and be able to take John's advise.
Steve (2008 Bounder 35E Ford Chasis)