I think that is now being considered by beekeepers, like me, who only have canola honey going into winter. The granulated honey needs the extra moisture in order to be dissolved by the bees. So some have successfully put plastic right over the cluster and as a result have seen the bees using the moisture that forms on the perimeter. The need for winter cleansing flights also seemed to decrease. When you have very few days for cleansing flights, some winters with none for months, needing fewer is a bonus.
It is normal for bees to do cleansing flights and die in the snow but some winters it is excessive. When you gotta go you gotta go, so some flights are happening in colder temperatures than they should resulting in many dead bees unable to make it back.