I tend to plan in scenarios like chaosmagnet does, and mine also involves being stuck in snow for a couple of days.

In that light, your kit looks pretty good, but you might want to think about adding things in a couple of areas:

1. Fire starting: you have a zippo and matches. Maybe add a couple of dollar store bic type lighters. I would also probably add in a few candles "just because."

2. At least in winter, a bivy bag or (if room) a sleeping bag. Even an old wool blanket.

3. A small stove and cup to boil water in, along with some tea/coffee/cocoa/soup etc. If stuck, a warm meal or cuppa can be a big moral and energy booster. Personally, I have to have that morning coffee. The stove can range from very simple esbit type on up. For winter use, I prefer propane or liquid fuel, but just about anything can work. (lots and lots of threads on stoves on this site!)

4. Meds: whatever OTC meds you might need (e.g. pain, allergy) and any prescription meds you can't do without for a few days.

These are just refinement suggestions. You are already 99% better equipped then most of the folks out there.

And welcome aboard!