Okay. So. That was bad.
He retraces their steps. Their Endures won't run out till a few hours into the next morning, which gives them a while to get out, if they can, and hopefully this is the obvious place to return to. He'll prep more Endures but - maybe not enough for everyone, they do have coats and can load up one person with extra coats if the rest of them have Endure Elements on (and that's assuming they all make it out alive), if he can think of first-circle spells he'll need in place of the Endures that might be useful for extraction. Tomorrow's supposed to be a Create Food day but they can all go hungry for one day without it being the end of the world and then eat heavily the day after tomorrow to make up for it, if he needs the third circle spell. At second he will definitely want Calm Emotions, maybe more than once.