When I saw your recommendation, I checked them out and ordered two pairs — one for yours, truly, and one for my wife. Funnily enough, I ordered both in the same size. Plus, I also got some plain merino socks from them. I can't wait to try them tomorrow, my feet are freezing!FWIW I got some Danish Endurance merino socks off Amazon the other week. I take size 47 in Shimamo shoes / 31 Adidas and the 28.5 - 30.5 cm socks fit me fine. Obviously I've only worn them a few times but they kept my feet warm enough in the snow last weekend (the shorter ones are good, too).
These shimano shoe covers will just about go over my size 47 Shimano shoes and seem to do a good job of keeping the wind and rain out. Altrura Thermostretch in XL are a bit roomier if you can find them in stock anywhere.