UPDATE!
Got a call from a local to say the badgers had been pulling comb out from the tree so decided I would have to remove the bees asap rather than wait until later this week.
Took the chain saw and a nuc and trudged the 3/4 mile to the site only to find it very quiet. Had a look with my endoscope and still no sign of life.
Set about removing the top of the log to find no sign of any bees, not even a dead one!
I can only assume that they filled their bellys with food and absconded in the warmer weather to somewhere they thought was safer.
Fingers crossed they make it but I'm doubtful!
View attachment 24561