I've spent nights in snow caves, and if you have the right gear, it's no problem. I actually like it! But then, I'm known for carrying every piece of gear available. Flashlights, 2 stoves, Gortex Bivy bag and gortex sleep system rated to -40F, Gortex tent, MRE's , etc. Big mistake, is people get ready to go, and say, "I'll never need this", and leave something behind. Yeah, leaving your 2nd bottle of fuel, 2nd heat source, etc etc, saves a few pounds, but if you're stuck above the treeline, you'll suddenly wish you hadn't lightened your load.
Those Chinook helicopters are unbelieveablely loud. Today being nice and clear, and no sign of movement, I don't take as a good sign. This is also when the 2 $40 high volume smoke grenades I carry are priceless. It's also why my pack weighs 80 lbs.
My prayers with their families.