Given the relatively mild winter you can expect, the overnight dip into the teens should cause no freezing problems. It takes sustained freezing temps. to freeze a tank full of water.
If an overnight freeze was predicted, I would turn on the hot water heater and leave it on. Open the drawers and cabinet doors to allow the warm air inside the camper to circulate through the areas that likely contain the plumbing.
Run to propane furnace to keep the interior temp. about 50* or so.
You'll be fine. We camp in much colder weather in CO and that's what we do. No problems to date.
Have fun. Don't shoot too many opossums. Save some for the next guy. :W