Fresh tank in cold weather

[Toy hauler guy]

I have a 2015 Dutchman Voltage 3970 with the all weather package.
My question is about the fresh water holding tank in cold weather. I have three tank heater switches for my black tank and two gray tanks. However, I do not know how I keep the fresh water tank from freezing up or is that a concern?
I spent last winter in the camper had a campground that had city water hook up. But I am currently in a campground that does not have city water hook up. So my freshwater tank is about half full and the temperature is dropping into the teens for the next few days.
I just don’t know if the freshwater tank will stay warm enough?

Thanks
Toy hauler guy