This seems the most likely explanation, but it is still extraordinary. Being able to survive in cold is one thing. But being able to survive being placed in liquid nitrogen for an extended period of time? That's incredible.
I dunno, have you looked into the human suspended animation with sulphur? A layperson could say: "wow, it's amazing the humans adapted to go into suspended animation when exposed to the cold and an atmosphere of sulphur!" It's not really something we adapted to, it's just another accident of our biology. https://www.ted.com/talks/mark_roth_suspended_animation
All life is a hack! All organisms are just pushing the minimum code change to get a leg up on everything else. Loopholes are everywhere.
Once you solve the problem of your cells freezing over, I don't think any additional cold is going to be much of a problem. If anything, the colder it is the better off you are due to the slowing of chemical reactions. There's a reason we freeze things to preserve them.
