Bumblebee nests:

Elothir

Does anyone happen to know whether the next generation of queens hibernate in the original nest over winter (which dies off), or do they find another spot to hibernate in? Most places just say they leave - mate - forage to store up fat and then hibernate underground without specifying if it's within the original nest or a new hole somewhere else.

Seem to have a nest in a patch of ground/the lawn I was intending to dig over and don't want to go disturbing any sleeping bees this winter.

Alan Clark2 in Liverpool

Queen bees do not hibernate in a nest, they find a hole which is just big enough for them, then in Spring they build a new nest.

https://www.bumblebeeconservation.org/how-do-bumblebees-hibernate/

wild edges

The nests tend to be full of parasites and mites by the end of the season so not a great place for bees to hibernate. I don't think bumblebees have as rigourous a cleaning regime as honey bees so the nests get pretty grim after a while.

Elothir

So basically it is that the queens for the next year fly off and find a cozy spot to hibernate in, so there isn't anything left in the old nest come winter. 

I had actually looked at the bumblebee conservation site, which does imply that the spot they hibernate in and the old nest are not one and the same, but didn't seem to outright say it, and since finding out it actually is the same when I shove a fork into it is a little bit too late I wanted to make sure well in advance of doing anything.