glad you asked Gavoon. Dms often say never expect things to go as planned.
but in terms, out of character those warriors have been through the wringer. the cracked carapace negates much of their armor class and the biting cold is numbing their senses and movements making them much more manageable. now mind you, they're still a large threat, the more time a warrior has to mill about, the more mutations it's body can devolope to deal with the new harsh atmosphere.
so while they are manageable, i dont expect them all to be dispatched in a single turn. just as i didn't expect many of the things to be dispatched in a single term save for the unlucky sod that went up against the sentinel.
also, the players have a bit of luck on their side in a sense in this senario, the ice storm is throwing down child sized hail, so in online gaming terms or DnD terms, the current foes could be concidered to have a DOT on them, if they fail a reflex, they take damage, and given their mobility is down untill they mutate an adaptation, that's a very likely threat.
also, the gaunts up front aren't actually burrowing... they're being smacked by ice
Never Give Up, Never Surrender. for it is better to burn out than fade away.