This generation, on both sides, has not fought a winter war.
Neither has the US Army. Do you really think they forget? Come on, get real.
In addition, most people’s winter garb—even in cold areas—are not designed to live in for months. I have some boots from my time living and working outside in Northern VT and NH. I seriously doubt there are 20 similar pair in my town in MA. They were expensive and ugly.
I would not want to go to a winter war in the everyday winter boots I own. I strongly doubt the every day Russian is getting good winter clothing.