[Autumn]

With insulate I'd prefer if it were a lower skill point cost with upwards to 30% ice resistance on it, keeping it not triggering ice sheets basically solves frostbite as an issue completely, and having it cure celcius and frozen is a good idea, similar to how Priest functions I'd rather it only grant immunity if it cures those statuses, a solid duration like 3 rounds would be a good starting point for that specific effect.

Not a bad idea is renaming it to Cryotherapy and having it heal a target by consuming ice tiles around it, cure celcius and frozen and grant immunity if cured, then give 30% ice resistance as well.

If its meant to be a support skill, it doesn't have enough utility at the current moment to make it worth a slot really.