Dang, you got 2 threads going.
We camped a few years ago for 4 days. Electric blanket wasn't enough with 26 degree lows. I bought a utility heater to add to the tent. That helped, with 30 mph winds it wasn't enough. I bought a large trap to cover the whole tent. That helped a lot. They help with keeping the cold air in if you use an ac and keep the wet out when it rains.