Your water will freeze up fast...for sure if it's just coming from a garden hose spigot. Your holding tanks will freeze also. Huge damage if those two things were to happen and I'm pretty sure they would.
now if you could park somewhere that has electricity but you could go into someones place to use the bathroom it might be ok. You would go through some propane though but you could use a electric heater some to offset that.
I have stayed in mine overnight at a place where i snowmobile 3 hours away 2 or 3 times a season.
But I get to park 6ft. away from a heated bathroom with hot showers. we have no water in the rv in the winter..just drinking water in a jug.
we have a great time but if it's below 20 the furnace runs almost all night long pretty much non stop!
Sometimes we stay in different places with no facilities if it just overnight when we are sled ridding. we just use the bathroom at restaurants before we go back for the night...lol.
We can pee in the toilet in the camper because i put in like 5 gallons of the pink rv anti-freeze.
never had a prob doing that.
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