Two lower cost suggestions
ONE: For reasons other than cold I took to filling the on board tank and using on board water... The tank is insulated and heated by the RV's furnace on my Class A. Worked very well and solved the "other issue" (over chlorination of city water) also made half my hookups easier as after my wife died I could go 3-5 weeks on a single 80 gallon tank so, moving every two weeks, I only hooked up every other campsite.
Page 2: I took a standard white "potable water" hose, A string of incandescent rope lights. Some patterned Duct Tape (They have lots of different patterns) and taped the rope lights to the hose.. Feed them power through a thermostatic outlet adapter (Designed for Things like stock tank heaters or eves heaters) and when it got down below 35 The hose lights up.. Very pretty. and the heat from those old fashion incandescent lamps warmed the hose.
Won't work with LEDs though. I think I still have that hose if you want it and can come get. NOTE it is not for sale.. IT's for "Get between me and the trash can".