I would be concerned about freezing lines in those temperatures if the 20's stuck around for any length of time but I would be more concerned with finding a campground that's still open in NY in mid November. On the bright side, the long range forecast is calling for temperatures in the high 40's-low 50's through mid November in NY. If you find a campground, why not just winterize the camper, bring bottled water for drinking and cooking, and use the campground facilities for everything else. then you can just concentrate on having a great time and don't have to worry about anything happening to the camper.