+1 for only one pair of socks and spacious shoes/boots, I was told like OP noticed that sock layers don’t work for feet and you should instead rely on having a layer of air as thermal insulation.
Also, if you want a temporary source of heat there are small pouches that you can pop in hot water for a few minutes and that will stay hot for 5-10h, the ones I used were single use but I believe reusable ones exist. They rely on an exothermic reaction instead of batteries.
+1 for only one pair of socks and spacious shoes/boots, I was told like OP noticed that sock layers don’t work for feet and you should instead rely on having a layer of air as thermal insulation.
Also, if you want a temporary source of heat there are small pouches that you can pop in hot water for a few minutes and that will stay hot for 5-10h, the ones I used were single use but I believe reusable ones exist. They rely on an exothermic reaction instead of batteries.