Like the question asks, they are all currently in garage which have gotten major frosts where the whole pot freezes. The first time, I forgot to put some pots back in their growing tanks and they got frost bite from the drying air. They're still Ok though.
I'm guessing the temps get to about 20 or less at times?
They all make it fine in my conditions as long as they are covered from the low humditity.
So does it really matter how low the temps get? I've never really lost any vft's due to the cold, its always because of something else like the wind, fungus, ect...