I have not used that particular brand but the Alpaca socks I have used in the past were very bad about shrinkage to the point I had to give them away.
I have been using the FITS brand of socks for cold weather. It is the heavy expedition model and is 100% Merino wool on the inside. Last extreme experience was in Alaska this October fly fishing with water temperature in the mid 30s. Very pleased with the warmth they provided even after hours of wading. They wick very well, and my feet were never damp.
https://www.fitssock.com/products/heavy-expedition-otc?variant=32531167019057