Well I'm no expert, but it seems to me that the odds of surviving a a full-blown disaster in mid-flight are so utterly miniscule that they're hardly worth fussing over, from a preparations point of view. It's takeoffs and landings that are at higher risk, with some potential for preps and initiative.

A flight would (I think) be some five miles up while over Greenland. If the aircraft is intact, that buys a fairly decent glide path. If you hit the ground or ocean early, the odds of the aircraft being intact are pretty darn small.

IF you are conscious and able to move when the aircraft stops moving, all you can count on is the clothes on your back. I wear non-synthetic clothing on flights, with wool socks and grippy shoes, and wear a smallish daypack that I can bug out with. Anything larger is a fantasy -- you need to get out, get out, get out NOW NOW NOW. You are not going to be dragging your junk out with you. Smoke will kill you quick.

BTW, I generally hate flying. Bloody sardine cans. Nothing romantic about it IMO. YMMV.