I've hibernated my adult rios between 60-70 several years with no problems at all. However I had much much better breeding response from my males when I droped them to 52 for three months just like my gilas....my temps tend to fluctuate in my hibernaculum by about 10 degrees throughout my winter cycle because its not quite cold enough to drop temps clear to 52 early in the winter and later come springtime. Several beaded breeders from warmer climates urged me not to hibernate them below 60 but my hands on experimenting showed me they were WRONG. There is still a few tricks to learn in the helederm field bro. Don't get mystified by anyones hype trying to sell ya something or assume a cookie cutter approach is whats best always.

Enjoy the holidays folks!
Peace n Happy Heloderms