Some dead bees laden with pollen

[greengumbo]

"last winter they were all tucked up by now"

OP the winter cluster isn't some magically static state that bees enter in autumn then leave in spring. it's a dynamic situation dependent upon ambient temps. Bees will be out and about even in the depths of winter if temps are suitable for flying (mine are back and forth to out neighbour's Loquat trees evne when snow is 2m deep on the ground.

AS per other posts - the bees probably just a bit too tired/cool to make it in. or caught out by a sudden shower?

Absolutely but we had terrible temps from October all through winter and the last snowfall in May. Never saw them once between end of Oct and February - not that I was out 24h watching - wait till I get that webcam set up