I have trouble with the old feet too! I have tried all sorts of socks to try and keep warm.
I bought some ski socks similar to
the ones in this link At that price they are worth a go. The ones I got did have a percentage of wool in them but they are out of stock. They have plenty of good reviews but like my books, they keep the poor ones at the top, front and centre. (There is also a link on that same page to some wool thermal socks which I haven't tried.)
They were bought for cycling really but because they are ski socks they are better at going down hill!
Because I have chunky calf muscles (!) through lots of cycling and walking they were tight below the knee. So I got the scissors out and chopped off the elasticated bit. I now have four pairs of very warm ankle socks to lounge about in.
I recently bought a single pair of 'proper' walking ankle socks from a mountaineering shop in Kirkby Stephen. They cost £20 (!) but they are great walking socks.
I suggest that controlling your blood sugars is the most important bit.