I've read all kinds of unproven theories. An over abundance of honey doesn't always pan out. In very cold weather bees head right for the top cover and then can't get to the honey below. Leaving a super on top of two deeps results in an increase in volume of the hive to heat. Knocking the hive down to just two deeps max in the fall forces the hive to decrease the population so it doesn't consume so much in the winter. Obviously location will make a huge difference on how successful these theories are but in my neck of the woods two deeps / three mediums is the norm for overwintering.
Just to see what would happen, I left two hives unwrapped. They seem to be doing as good as the ones I wrapped with insulation. I run two deeps and left a medium full of honey. I know its not very scientific but it seems to me as long as they have plenty of food and are vented good, healthy, queenright, etc.......they will make it.