The question of hibernating large colonies has occurred to me a couple times since getting back into this hobby this past year. Most of the colonies I have that take winter diapause aren't too large to fit in my mini fridge for the winter ... but with any luck, they will be eventually. Moreover, I'm moving towards wanting to keep many of them in vivariums, which obviously wouldn't fit in a mini fridge. I live in NYC, in an apartment, so I don't have anywhere outdoors to store them, and a mini fridge is about what I have space for. So unless I literally buy a second full sized fridge, I can't think of where I could put a large colony.
I could probably get used to keeping my bedroom around 65 or so degrees in the winter if that were an option (I notice my pennsylvanicus slow down considerably in that temperature range), but as far as I know most temperate species like to diapause colder than that. Plus, I have some non-diapausing ants in the room too.
I've seen this question asked here before but never with conclusive answers. Anybody have any ideas/what do you do with your large colonies?