I've always assumed humidity, temp and feeding work as one to help resumption of egg laying.  I think that's why you will see brooding start in Jan. in cold regions. Open honey absorbing enough water caused by the high humidity from the winter cluster forcing the bees to eat more of the reconstituted honey which stimulates egg laying in turn driving the engine to eat more stores to produce more heat. 
That's just my own thought. Could be way off.

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