Traveling should be relatively easy, as you can use the dash heat rather than or in addition to the furnace. If it's not too cold out, that can often be enough to keep the unit reasonably comfortable while en route. (Cracking a ceiling vent in the back, preferably with a max-air or similar cover, helps to pull the heat through the coach.)
Staying in one place needs the furnace and that does use a good bit of propane, depending of course on the outside temperature.
If you don't have enclosed water tanks/plumbing, having running water will be troublesome if it's below freezing. Enclosed tank bays usually have some provision for heating them, often with a small duct split off of the furnace, and such units usually can be used in sub-freezing temperatures so long as the furnace is used for heating.