I tried the shopping bag (loaf bread bags fit better) in all possible combinations. I found the best to be foot, thermal sock, then bag, shoe and finally....toe covers. Not good without covers and then marginal. The sneakers were probably why they worked---loose fitting. But as tsl said, the wind stopping is the outer layer and insulation is next to skin. Otherwise it's like wearing a shower cap under a skull cap then cramming a helmet on and wondering why your head is still cold, or why latex gloves under insulated gloves produce nothing but cold, sweaty hands.

Right, Lake boots are not cost effective for as little use that we'll give them in the south. I want to stay with SPD options. I'm not going to use booties, as much a pain in the butt as the toe covers are, booties are out of the question. They would be fine if you get on the bike then ride a decent distance and get off. For stop and go errands--they suck.

The Garneau boots that Patrick showed were my exact conclusion as to top of the limited use/limited time (as in bike/winter specific) option in mild climates. Even more justified by the distance that he rides each way.

I'm gonna keep my eye out for end of winter sales and "see how low they go". Patrick and I won't be in competition for the last pair, my foot is small enough to use double digit metric sizes.

Barring a deal on those boots, I think I will look into electric options as a heat source since heat trapping doesn't seem to be an efficient southern US solution.