We go on a trip each New Years, it's usually 5 nights. Last year it was cold, nighttime lowes ~25* and we have no special cold weather package, and we went through a 30lb bottle and about 1/3 of another. That was running a lot of furnace at night and occasionally during the day too.
Other than that we usually get 15 nights out of a bottle. Furnace is the killer; water heater, cooking and fridge hardly consume any.
2007 Chevy Duramax LMM/Allison
2012 Jay Flight 29QBH
2012 Jay Flight 26BH (Sold)