For the past eight years we have left Wisconsin and headed to Arizona in February. Sometimes it has been very cold when we started. All liquid things in the pantry, extra bottled water, etc. were in danger of freezing. I hang an indoor/outdoor thermometer in the camper and take readings as we travel along. If it close to 32°, we stop after fueling up and turn on the furnace. We monitor it and turn it off when the temperature gets into the 60’s. Usually by the second/third day we are far enough south not to worry about it. This has worked well for us in cold weather travels. Happy Trails.