Here’s some stuff that’s good know, quoted directly from my public domain reprint of the The ABC and XYZ of Bee Culture (1947 edition). It’s from the “Wintering” section on page 686:
“Tests have shown that pollen supplements fed to unprotected wintered-over colonies beginning late in February to advance brood-rearing will yield one to two packages of bees [30 to 40 thousand bees?] about April 20… This control over brood-rearing based on the pollen factor makes it possible for the colony to develop in spite of unfavourable climatic or seasonal conditions… Forty pounds [18kg] of honey stored in dark brood combs should be present in the top hive body when 10-frame standard equipment is used.” The common wisdom for Newfoundland beekeepers says that most colonies in 2-deep Langstroth hive will need 10-12 full deep frames of honey.
How much wrap or insulation is used for wintering hives is determined largely by local weather conditions. In other words, all beekeeping is local beekeeping. Except for ventilation through an upper entrance, there seems to be is no universally correct way to winter hives. From page 694: “…beginners and those who have some doubt, [should] follow methods that have given good results… in their own immediate locality… It will bear repeating that localities differ so that what will work well in one may not in another. Specifically where there is excess moisture, packing [i.e., insulation] may do more harm than good, especially if it freezes.”
It’s common to wrap hives for winter in black roofing felt, but that stuff can get messy sometimes when it gets soaked in rain and then freezes. The final spring thaw can leave mould on the insides of the wraps. I know many beekeepers outside of Newfoundland who never wrap their hives. They paint them dark green so they warm up in the sun and that’s it. I’ve done that a few times and haven’t had any problems with it, and it’s one less hassle to deal with. I sometimes wrap my hives because everyone else is doing it, though I’m not sure it’s necessary in every situation. I’d wrap my hives that are out in the open and battered by strong winds all winter. But if they get some sunlight and they’re painted dark green, is it really necessary to wrap them?
From page 687: “The winter cluster will form in the upper hive body provided the stores are contained in dark brood combs and there is a small open center free of honey. Under these conditions the cluster will cover combs of sealed honey or if they have not been used in brood-rearing, the bees will cluster lower down in the hive.”
I considered switching to medium supers for both brood chambers and honey supers since I got interested in beekeeping. I probably would have done it from the start if my nuc boxes were set in medium frames instead of standard deep frames. Mediums are lighter and easier to handle and all the hives parts are interchangeable. Apparently it’s better for wintering bees, too. From page 689:
“It is very necessary that there should be inner communication between the combs [in the winter]. When they are deep and all in one story, the bees must pass at the top or bottom to get into another position in the cluster… One can readily see that where there are shallow chambers [e.g., in medium supers] there would be two spaces which would allow the bees to pass back and forth… Where shallow chambers are used during the winter, the bees are able to circulate all through the cluster moving to where the stores have been consumed.”
The “two spaces” are the space between the medium supers, or the vertical space between the frames. Basically, the smaller frames make it easier for the bees to move from one side of the frame to the other. And they can move quick enough so they don’t freeze to death. The bees are more likely to starve on larger frames in the winter because the cluster can’t move to the other side as readily. There’s too much ground to cover. If they can’t make it to the other side of the frame without freezing, they stay put — where they may eventually starve.
November 2018 Postscript: I could have deleted this old post, but I tweaked it a bit instead. I guess it has enough info that could be useful. I’ve always been tempted to switch to all-medium supers because I’m sure it would make beekeeping much easier. I still am tempted.