I've dumped a canoe or two, but thankfully not in an ice-cold river. I've also been fat-fingered a time or three, but thankfully not full-on hypothermic.

I think you've created a decent backup kit.

The big thing that catches my eye is "calories -- lack thereof." You've obviously thought about this. But IMO, on the edge of hypothermia, you need to buy time. For me, a handful of Werther's Originals for instant sugar (and a hug) plus a Power Bar to blunt the sugar crash later could get the internal furnace roaring and an external fire built.

Maybe stow these in a bright red clip-on bag that you remove at night?

My 2¢.