OK, here we go. Mark at the local full service outdoor store actually called Superfeet and talked to them directly. Just try and get that kind of service at the Sports Authority. The principal difference between the Wintergreen Cold Weather Insole and their Maximum Cushion Green Insole is a thin layer of Outlast insulation. I decided to go ahead and order them and buy a couple of more base layers too.

Well, they're here and I measured them. Beneath the ball of the foot they are 0.185"-0.190" thick. The old insoles were 0.145"-0.160" thick and obviously not intended to hold in any heat. I might line the bottom of the shoes with some aluminum tape as well. In any case, I'll let you know how much improvement they offer when I make my next frigid commute.