Well, on that trip years ago I was crossing Montana in October and had never been so cold. I stopped and dug out that vest and I think I smiled the rest of the way back to California.
That trip in about 1996
Now my Gerbings jacket liner lives in my panniers year around. I love how little room the liner takes up and the outstanding temp range it will handle.
BTW, I also have the BMW Pro Winter glove. I don't get to use them to much being a California boy, but they sure are nice.