I thought these pictures showed the insulation of an occupied TBH quite well. Taken this morning.
Googling around, most pictures of hives in snow are similar, showing no melt above the cluster, which is about two-thirds of the way towards the back of the hive as seen here. (Some have no snow on them, but it’s not clear if the owner had opened them.) So I reckon this hive’s roof insulation is up to scratch.
Some websites mention that you should check your entrance is not blocked by snow. This seems to be an issue when you have a ledge or landing board in front of the entrance. On this hive, the entrance is on the vertical face you can’t see, so snow can’t lie over it.
Hefting the hive, it’s now heavier than a week ago due to the snow, so I can’t tell how rapidly the occupants are getting through their stores; but they seemed well stocked last week, and content when viewed through the window.