Under the catagory of feeding ,Watering is over looked. Long periods of
cold dries out the air. Honey has very little moisture (18 % +or- a smidge)
but is more usable if some moisture is around to thin it. Oh I know they
will  even use sugar crystals dry but it does not mean it is best. Water is
brought into the hive even in the winter if it is needed badly enough.
Sometimes that means bringing in snow, I have seen this. That is why when I
see bees outside the hive in temps below 43 degrees above. I know something
is going on inside and I dont know for sure If they need food or water. I
give them thin syrup in a warm deep super on top of the hive where they can
move up in a cluster and get it. If i guess wrong its only a waste of a
little time If I guess right I save my hive. Most of the time Im right.
Timing means a lot,is the hive demoralized,is the weather changing too fast
are there too few bees? One thing is for sure it is better to have it and
not need it than to need it and not have it.