What do you do when you have a camper in the yard, nowhere to go and cold weather approaching? You take all of the things you learned on the portal and perform an experiment on cold weather camping! There were freeze warnings popping up on my cell phone most of the day and my pup is sitting in the yard unopened since I brought it home out of storage, I figured it was time to open her up and put her to use. I already did the greasing and oiling to the lift system last weekend, but had not yet popped the roof up, so I needed to give it a test. The temp was to get to as low as 30*F in our area with light winds. So I popped her up and set her up for the cold. I plugged in to shore power for this experiment for max cold weather comfort. Maybe I'll try without shore power next time. Here are the things I did to prepare for the oncoming cold: 1 - Used the Popup Gizmos on the bunk ends and Reflectix in the windows. 2 - Used a 1500 watt electric heater. I've used the pup's furnace before and I knew it worked well, but I wanted to try the quieter electric heater. 3 - Blocked off the unused bunk end with a sheet to create an smaller heating area. 4 - Use the heated mattresses. In addition to wanting to test the cold, I wanted to see if I could make the harder than desirable mattress a bit more comfy. So under the mattress I tried two things. On one side I slid the Harbor Freight floor pads. On the other, I placed a Thermarest self-inflating mattress that I've had in my camping supplies for years. When camping, the DW and I have always use sleeping bags, so I zipped two sleeping bags together, threw another one on top and brought out an old comforter for insurance. I headed out to the camper at 9:30 PM. The DW was a trooper and joined in. The outside temp already at 45*F. I turned on the electric heater and set the temperature to maintain 55*F and turned on the heated mattress. I set the heated mattress regulator to a setting of 2 out of 6. I've used the heated mattress before and knew that would be plenty warm. We had the laptop with us and we watched a movie (The Island of Dr. Moreau-1977) while waiting for the temperature inside the pup to stabilize. After the movie, we hunkered down. Conlcusion: The outside temperature didn't quite get down to the promised 30*F, but it did get down to 32*F. The heater had no problem keeping up as it turned on and off all night. It did keep the temperature inside the pup in the mid 50's. We woke up to a temperature of 57*F inside the pup. I was toasty warm under the sleeping bags. Overall sleep was good. I'm a light sleeper but got a restful nights sleep. We ended up using the comforter we brought out for insurance, but I took it off in the middle of the night because it was too warm. I got out of bed and moved the sheet that blocked off the unused bunk end and could feel it was much colder back there. So blocking it off was well worth the effort. Using a blanket to block it off would have probably worked better. On thing I noticed was that the humidity indicator on the thermometer was at 45%. It was at 28% when I went to bed. I guess our breathing kept the humidity up, but there was no sign of moisture on interior of the tenting fabric. The mattress pad and floor mats I put under the mattress definitely helped. The Thermarest pad did a better job than the floor mats. I will order a new one (or a similar knock off) for the other side and use floor mats for something else. I now have confidence that by prepping like we did, cold weather camping is not and issue for our pup.