Not sure what you find "funny".
I find it funny that folks buy a totally portable and self contained home on wheels, then for some odd reason what to stay tethered to an extension cord while traveling?
May as well save yourself a lot of money in the cost of the RV and wasted fuel and simply drive a econo car and book yourself into a nice Hotel Room.
One pair of GC2 6V batteries easily powers my home fridge conversion, provides lights, water pump and yes, even heat via the RV furnace for not only overnight but around 20 hrs and still have some battery left (not dead). It doesn't take much planning, effort or cost to make most any RV independent enough to travel for days at a time without ever needing commercial power.
OP doesn't "want" a generator buzzing in their ears all night long. Why in the world would anyone need to run a generator overnight in "cool" weather to just run the furnace? The RV furnace doesn't require 120V AC, just some 12V battery.. All you have to do is make sure you have sufficient battery capacity to handle the 12V loads for the time period needed.. Recharging the batteries happens while you are cruising down the road in your land yacht ..
We overnight all the time, WM, Rest stops and the likes during warm and cool weather and have not once needed commercial power nor have we ever ran our generator overnight.
Just takes a bit of preparation up front.
