It seems like I'm neglecting the poor things... but the truth is that the heavy lifting for winter prep was done in my apiary in August (honey check, mite checks, queen checks, comb drawn out completely), September (queen checks), October (mite treatments...)

So at the point we hit winter, I'm ready for a break!

Bees are pretty alien. They are a superorganism that goes from the size of a toy Poodle in winter, to the size of a Standard Poodle by May. So over the summer, my bees have one extra-deep box (or a deep and a shallow) for the queen, and then 3 honey supers.
In the winter, they only need the extra-deep box (or the deep and shallow).
It is normal for the number of bees to go down dramatically in the fall. The size of the fall cluster is about half that of peak summer population; so about half the hive. The other half is honey. Bees actually don't like to cluster on honey; they want to cluster on empty brood comb. They will in fact die if they only have honey frames to cluster on.

One of the most challenging aspects of overwintering bees: the winter bees must be numerous, and must have been pampered by their older sisters. Bees that nurse younger sisters, then forage, only live 6 weeks total. That's 2 weeks foraging. By late Oct, all those bees are gone. The last 3-5 frames of brood are the only bees left at that point. They did not burn their candle at both ends caring for sisters and foraging, so they have the reserves to make it through winter.