UP-Date. Here in Houston for the last few days it has been in the high 20's at night. I placed a small electric heater in our 183 and placed the heat selector on 1,000. It is a three position switch listing 500, 1,000 and 1500. Checked it this morning when it was 27 deg outside and the thermostat in the trailer was showing 65 degrees. The thermostat on the little heater was not all the way on high. Couple of thoughts here. A. The trailer is well insulated and B. One can run a small electric heater down into the 20's without having to use the furnace. On a day it went into the 30's, I had to put the heater on the 500 setting as it was too warn. As long as one can keep the pipes from freezing, cold weather camping will not be a problem. This was with the slide-out out, meaning more space to heat.