Lots of good answers, but a few more questions are also in line.
How is your water heater powered? Are you on shore power? How cold is it outside. I have winter camped many times in trailers, pop-ups and Motor homes the longest time length was a month.
Is it a expense issue? , is your unit on gas or power? My current camp buddy has been in his camper as a work camper in an area campground for over 18 months. He has never turned his water heater off. The elements inside the units in a home are not much different than a camper unit and they are never turned off once on and they last years. I replace my first heating element in my unit last year and it was 9 years old.
Look at all the pros and cons and do some test to see what works best for you at the time, but be aware of your units location, and pipes freezing. Happy parking