It's somewhat hard to see where the original cavity was that was available to the bees given the massive disruption, but the section I've highlighted shows a harder surfaced section which appears to have been at least part of the cavity area available to the bees. I doubt that they had access to the spongy material. Insulation seems to be of far more significance to some forumites than it is to honey bees
. It's in our nature to anthropomorphise their activities. For instance, we deliberately heat our living spaces but I don't see bees doing that. Their primary focus is surely to protect themselves and their stores from predators? Out of interest, do you know where the entrance was?