Fridge and propane

Maybe this will give you an idea. I just got 22 days on a 20lbs tank towing my camper from Alabama to Glacier National Park and back. I hit a few other places of interest on the way out and back as well. Dry camped for 5 days, the rest I had shore power. Hot water heater was ran daily with propane, and furnace was ran for 2 nights. Low temps were high 30's low 40's and highs were in the upper 50's.