When I taught snowboarding, I kept several items on me, but not for survival:
...
- Bandana for wiping goggles and other purposes
I did not see goggles mentioned previously.
Goggles should be standard EDC ski equipment, but if
not, should be included in winter survival gear.
Of course cold, but also Wind can be the big enemy.
So, an extra layer of pants, thin wind-pants being a minimum.
A decent-sized parka hood on at least one jacket.
Face-mask that breaks the wind like chamois leather.
(A Balaclava will NOT due for this, even though I like it
as a hat and improvised mask.)
2 knit ski caps. (May not be needed of you have a foam
insulated helmet.)
People at downhill ski resorts rarely get lost, but it does
happen. Consider a small GPS.
I believe that proportionately, snow-mobile, snow-shoe, and
cross country skiers are much more likely to get lost.
OTOH, downhill resort skiers are less likely to have survival
gear.