Camco 25-Foot Heated Drinking Water Hose

I have a 4 season travel trailer at a campground in Indiana. I have also skirted my camper with treated 2x4's with studs every 16 inches and added 1/2" treated plywood. We also leave our travel trailer heat set at 50 degrees. My well pump house is insulated and heated so I know that the pump is not froze and working and the camper is warm. I also have a heated spigot on the well house. 1. I tried the homemade hose, heat tape, foil insulation method and that failed due to a bad heat tape. So I wanted something more bullet proof. 2. Ordered the Camco 25ft -40 degree hose from Amazon just a few weeks ago, to go with a more manufactured approach. Installed it, hooked it up and it was "working" for a few days. Then the wether dropped to 10 degrees overnight last night. Today the hose is froze. The only variable is the hose and this hose that is supposed to work at -40 degrees does not work at 10 degrees. Waste of money and tons of frustration. Avoid this and any other hoses of this type. So disappointed and out $150.