Cakes are for precaution
BTW we're you providing the sugar cakes as a precaution, or were they short of stores?
David, what an interesting and fun question. Seems like you could weigh the hive a couple times over say a month of no fly cold either and divide the delta by the estimated (probably need to eye the cluster once) number of Bees and number of days. Let us all know what you find please.
Here are my bees finally getting into the emergency sugar cakes I put up in October or so.
Does anyone know how much nectar/honey/sugar a single honeybee will consume in a winter day,either in a cluster or when flying/moving around on a warmer day?