Greetings from another Alaskan!
Yeah, fire starting gear doesn’t do much in an area with no fuel.
I like trash-compactor bags as being torso volume but tougher than 40-50-gallon trash bags, although your students wouldn’t be bush-whacking, right? I leave them intact because then you can use them to haul water (or, hey, trash!) and if/when needed as a poncho, use a knife or your teeth to gnaw a head and two arm holes into it. A second such bag can be the bottom half of a bivy sack.
Next, I’d have a light. Just a $1 LED light from Walmart – to see your way but also be more visible if you need to attract attention, even while walking to and from school in the dark.
After trash bag(s) and a light, a $1 button compass IF they know how to use it. A bit of practice of what direction is town from 1) the airstrip, 2) the dock, 3) the fishing spot, etc, is super helpful ONLY if known in advance of a white out or night time.
So maybe a local map with compass bearings on it from common destinations back to town. Xerographic or laser-printed heat-set toner is waterproof (ink jet ink is NOT waterproof). Then take the printed maps and coat with the Rite-in-the-Rain secret sauce or the stuff sold to water-proof maps or (far, far cheaper per quart/gallon), Thompson’s Water Seal from the paint store for sealing a wooden deck works to waterproof regular old computer paper. Or just buy some waterproof printer paper.
Then 5′ x 8′ of poly-cyro (sold as window-sealing kits). Tarp, poncho, wind break. Plus 25 feet of line. I like 100- to 150-pound-test braided Dacron halibut line. LEARN YOUR KNOTS.
Trash bag, light, map&compass (and instruction!), poly-cyro, cordage . . . . . then what?
Clothing is important but bulky. Mirrors are stupid compared to a light – a $2 laser pointer is better than any mirror (mirrors require the sun). Water is heavy and freezes. Food is bulky and you don’t need any for 48 hours. Fish hooks – it’s a survival situation, not a fishing vacation. An EPIRB or PLB is incredibly useful but spendy. So I think my next item would be to double-up on the light – a different style, maybe a cheap headlamp. A Bandaid or two. Not TP but a few sealed towellettes which can be TP and hand washing.