To be on safe side you can add 6 foot heat tape in the control section where your fresh water hose connects. These heat tapes have matured and are safe to use. A 6 foot heat tape puts out as much heat as 40 watt light bulb and only come on when it gets close to freezing and cut off automatically when temperatures rise above freezing. You could simply plug in to the electrical outlet and drop tape into water pump compartment.
I used these heat tapes in my old camper to keep dump valves from freezing because they were exposed. However I would suggest you get good brand name one from places like Home Depot, not those cheap China ones.


https://www.amazon.com/Frost-King-HC...ords=heat+tape