Install a compact auxiliary heater in your camper. The simplest and most compact option 👍 https://amzn.to/3PAtPHM The vehicle's fuel tank doesn't need to be drilled into. The auxiliary heater can be removed and reinstalled in just a few minutes. It can then also be used in the garage, for example. Simple "plug-in" system. You can install this compact auxiliary heater yourself! More tips at https://www.kasten-wagen.de/ Many more tips on other topics can also be found at: https://granit-waschbecken.de/ https://www.kasten-camper.de/ https://www.huehner-kaufen.de/ https://outdoorkueche-kaufen.de/ https://tauchsignalgeber.de/ https://geld-versteck.de/ https://teichreinigen.de/ Have fun and good luck!