I work camp with my Montana, ALL the hot and cold water lines in the camper are now covered with foam pipe wrap and have heat tapes enclose with the pipes. I say now all are wrapped because today I put a heat tape on the last fresh water line that comes from the fresh water tank. Plus now I have installed the fresh water tank heater from Ultraheater.
In the underbelly you must drop the black cover to get to the water line. Your camper being new that mine should have the water lines buried in the insulation in the underbelly? Mine are just laying on top of what Montana calls there Attic package (a thin foil coated bubble wrap). The bubble wrap is supported by the black plastic you see under the trailer. The pipe in the basement can be wrapped and heat taped inside the access doors, or you could run a heater in that area. I will never use a heater in the underbelly that I could not monitor.
This is what the pipes in the basement look like after wraping and adding a heat tape, the pipes in the underbelly are done the same way.
