With temperatures dropping below zero in Colorado, I am wondering how cold can people live in a motorhome without freezing the water pipes?

Some RVs and some motor homes are ordered new with what is generally known as an "arctic package" or "winter package". This amounts to a pan of sorts on the underside with extra insulation. The water lines are above this insulation next to the floor, as are the waste pipes and water tanks and holding tanks.The water lines can have the heat tapes powered by an on-board energy source. Of course if the unit is not used during the winter months in a freezing climate it must still be winterized to avoid damage.

Anything below 20 will put your pipes at risk for freezing. They are less likely to freeze if you keep the inside of the motor home heated.

perhaps they are well insulated.