I sent back my lightweight Sealskinz socks because they were too small. They were replaced by a mid thermal pair more suitable to winter commuting. The new pair are still made by Sealskinz but are thermal, mid length and have a merino wool lining. I put them on and spent the day walking around the house in them. I must say that my feet were quite hot and were sweating after a few hours. They also make a slight rustling sound when you walk which is quite amusing. I think they will be the business on the bike especially in cold inclement weather. No more cold wet feet! Bring on the rain my friend!
My other purchase was a merino wool base layer from Endura. I bought a small one which fits perfectly and will keep me nice and warm when and if the cold weather arrives. It does itch a little though contrary to the claims on the packaging.