Really? Only 2? Good to know. I thought for sure 4 would be too few for them to heat the coop with their own body heat. I may have to try. I'm having issues with my Thermocube at the moment where in it doesn't seem to want to shut off at 3C, my hen house is reading +12 and I can see the power light glowing on it.
Right now the heat panel is right in front of them. Only place I can put its a small hen house, one side is the bracket for the roost, the rear wall is the access door and the other wall is my egg boxes + window.
The fact that we had stable power all winter is the only reason I believe they survived.