We went up there last night for an optimistic go at Blue John Rib. It was clearly not in condition despite car park temps of -5C
As Over the Moors notes, the thing needs to be sodden from plenty of rain before a few cycles of deep freezing and it's been very dry of late. We did Spare Rib which was fun, but which became less consolidated as we got higher...it was almost mild at the top around 10pm.