In your Northpoint I expect you will be able to handle the coolness better than my HTT. Last fall we camped with overnight temps down to 20 or 21 degrees, and day time highs only hitting mid 30's. I admit, I was a little concerned as these were the lowest lows and highs we had experienced in a camper. FYI, we were boondocking on top of it. We do not have an underbelly, so are tanks are all fully exposed and have not froze up yet
. Water in the tanks has a huge thermal mass, so it takes a long time to cool the tanks down before they will freeze. I have never had any issues exposed my low point drains breaking.
You will be fine, with taking a few precautionary steps.
- Put lots of water in your FW tank. This will get you through the night, and until the hydrants/hoses thaw out. Honestly, I am surprised any CG in WI will still have the water on in these temps.
- Disconnect your water hose, drain it and place it inside your cargo hold. Otherwise it will freeze solid overnight, and you cannot do anything with it, until it thaws.
- Have sewer connections? If so, disconnect the sewer hose from the CG system. It can fill full of frost over night. Again not a fun thing to clear out in the AM
- Water Heater, Pending on the unit you have, ether drain it and by pass it, or have it turned on and running.
- Plumbing, I suspect most if not all your plumbing runs through your cargo bay, and underbelly. So it would be best to provide some warmth down there. Also keep your cargo doors closed.
- Heat, It is probably best to run your Furnace. Your furnace will dump heat behind the water utility cabinet to keep it from freezing. Also some heat will make it to the tanks and help keep them warm. You can always run an electric incandescent light bulb (60+ watt) to produce enough heat to keep the wet bay warm.
I suspect you are already setup better than my HTT, and we have been down to those temps often, and we have had no issues, running electric heat and exposed tanks. Big difference, our plumbing runs inside the unit, under all the cabinets, so we keep the doors ajar.
Have fun, wish I was out there, stay warm