We have camped "dry" several times.
If your destination camp ground has electric you can use a little heater
to warm you and save on the LP and battery power.
You can even use 2 heaters if you have a larger RV.
You can run a heavy duty extension cord out thru your slide out
seal and plug it directly into the extra outlet on your power post.
This should keep you from kicking out your main breaker.
We bring drinking/coffee water in blue water totes by Alliance.
They come in 2 sizes and can usually be found in the camping or RV isle
of your favorite big box dept store.
IF it's not going to be much below freezing we still pee in the RV toilet but
hit the rest rooms for the heavy stuff. IF I'm really worried about freezing
at night I can drain that small amount into a bucket and pour it down
the toilet in the bathroom before turning in for the night.
How much of a camper are you
Sitting on the toilet seat of an un-heated pit toilet in winter can
be an exhilarating experience or not.
We just say it's all part of the ADVENTURE.
Flannel sheets or flannel lined sleeping bags are wonderful in cold weather.
We also use a down comforter on the bed and turn the thermostat down
to 55 F at night.
You can use a down sleeping bag that zips open and flat for a warm
In the morning we turn up the furnace and light the oven to bake
biscuits and also are perking coffee. These things quickly warm up
PS-- don't forget to pour some RV antifreeze down any drains you might
have used when you are finished. Stop at a dump station or use a bucket
to get remaining liquid out of your holding tanks.