Now I'm heavily committed to the concept of insulation I'm seeing the very lucid (sounding) arguments against it.
This is bound to have been debated previously but I've been absorbing the theory that the winter cluster has a reciprocal arrangement amongst the bees in that the more central ones suffer from an overall water loss whilst the outer ones gain water. This is from the respiratory water vapour rising from the central bees and an inability to lose water by "cleansing" trips outside. Gradually, positions are exchanged so that water and warming equilibrium in all the bees is restored. If it's not cold enough to force a tight cluster then none of this works and the bees dry out. It sounds convincing but I'm not sure.
I thought the conundrum was mainly about bees using condensation from the hive walls which I was disrupting by using insulation.
Another problem to worry about?