Cold feet!!!

[wahday]

When I ride in cold weather, I will sometimes cut off the corners of plastic shopping bags and slip them over my toes when I put the shoes on. Acts as a windbreaker and reflects a good deal of heat back to my toes. I imagine a "dirtbag" foot warmer strategy could be to have plastic shopping bags with you (they are small and light) and maybe slip them on in between sock layers when in camp (would be clammy and uncomfortable right on your skin). Noisy, but I would imagine pretty effective. And free (except whatever you bought that came in the bags...)

[Damnitman]

maybe USPS Tyvek envelopes?

[Slim]

On the package of the warmers it says not to use them agains bare skin and not to leave them on overnight. Heed those warnings! I didn't once anmd got a nice burn!

For down sleeping socks check out https://goosefeetgear.com/, they are the lightest ones I know of and very comfy as well as reasonably priced.