In SC and have 5th wheel Vengeance plugged in next to house. Last year didn’t get too cold and I kept an electric heater going in the camper, drained the lines at faucets and commode only, and threw some pink stuff in the drains for the tanks...keeping in mind that it stays plugged in, is there any more than needs to be done in my area? We don’t completely winterize due to spur of the moment travel year round.
Only you can weigh out your risk vs precaution you're willing to take. Looks like at least some areas in SC have multiples days with highs below 30 degrees.
I'd be concerned about outside shower, low point drains, and plumbing in the basement freezing. With practice, you can blow out the lines or fill them with pink stuff very quickly. That's what I'd do if it were my choice.
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