My understanding about bees feeding in winter is shaky at best; I wrote this in order to organize my thoughts. Would you please look it over and comment if I'm wrong? Thanks in advance.
In a TBH, bees cluster in the cold, consuming the honey they can move to without uncovering their brood. During periods where the temperature rises and they are able, some will break the cluster and collect honey from cells previously just outside the reach of the cluster and relocate it within the cluster's reach.
The problem occurs if there are long cold snaps, forcing the bee to remain in cluster and away from stores.
Assume we are still talking TBH, what are the options if we sense this occuring? Can we swap full combs from the back of the hive? At the extreme, we read of Dr. Mangum refilling comb with syrup, but can we do something less intrusive? Is there something else bees do to stay fed in cold conditions?