Aircraft preheaters at FBOs

I reached out to several FBOs in nearby areas and no one carries a portable preheater such as a propane powered one. Considering the temperatures are in negatives these days, I’m seeking advice on how other GA pilots go places without worrying. One of the FBOs said I can bring my own heater with me and if it’s electric they will offer an outlet to plug into. Let me know what you all do.