I use two small electric heaters ( both with tip over switches ), on low setting. I like using these on low because I am guessing they might last longer and be safer on low rather than high, but that's just a wild guess.
They run on a dedicated circuit I ran that connects to the CG pedestal 20A outlet, on a 10 gauge extension cord, so they are separate from the trailers normal 30A power cord. The two of them running on low pull right at 13A according to my kill-a-watt device.
At night, I found a full bed electric blanket to be too hot, so I got a electric "throw" at walmart. It is approx half the size of the queen bed, so it's nice in that it just puts heat on my legs and feet. It does an auto off after two or three hours, which works well for me.