It will probably be ok if it hangs out on the warm side in a hide but with that much of a drop it's probably pretty drafty in there. This is why tanks are not good for them without lots of modifications. How's the humidity sitting? There are numerous threads with suggestions on how to modify a tank and sounds like for that big of a drop you'll want to find the instructions for covering 3 side's in foam for insulation. Hope you can get it worked out!