I'm in N Florida too, and we had our first freeze this week. I wasn't sure what to do, b/c I have a 'cheapie' coop that has very little room inside but I felt I needed to step up a few notches with some kind of insulation. And it's hotter than anything in the summer, so I can't have a permanent filler in there either. I have a ceramic infrared lamp that I use inside for my finches to bring up the temp w/out raising the heat indorrs, but I'm really worried about putting something like that outside due to fire hazard.
But Cardboard - yep, I gots lots of that! Plastic bags? check! Bubble wrap? check!
thanks for the ideas peeps!!