I am understanding that you will be sleeping in the trailer at night and want to use the toilet during overnights on the southward voyage (rest areas and food/gas stops suffice for daytime relief). If it were me, I would put some antifreeze in the black water tank and flush with water. Then dump and operate as you would in warm weather if it is warm at your destination. We sometimes carry a couple of Arizona Tea gallon jugs to use for "emergency" flushing. Depending upon where you are going, and if you are staying until winter ends, you may not have to winterize before heading back home. Living in Florida, I have never winterized my campers. The coldest I have ever seen is 31 degrees for a couple of hours before sunrise. I have a carport in which I can aim a ceramic heater under the camper, and a thermo-cube that turns it on at 33 degrees. Just blowing a little heated air under the trailer keeps the temperature in the carport above freezing, but the temps typically don't get that low. In February, at Scamp
Camp in Sebring people often wear T-shirts during the day, or a sweat shirt if it's cool. I do, however, drain the water heater when I don't think I will use the camper for an extended period of time during the "winter" months.
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