Now THAT'S the Les Schwab I know. I'm glad they made it right for you. Do you get to keep the old rims, or are they taking those back? Hopefully they wad them up tight and shove them up the manufacturers rear end. Those were horribly defective.
Most wheels should handle the winter just fine. Unless you get serious acid on them (which would destroy the entire lip and not just parts of it) it usually takes a few years of neglect to get them looking like that. I had some wheels on my Mustang that I rolled on for three years through Utah winters without ever having any damage. And those were just "cheap" Enkei wheels. Deep dish polished lip and everything. Just like yours. If they can survive the salt encrusted roads and crap we call a winter around here, then I don't know why any wheel wouldn't hold up to a Montana winter too.