I think what Derek meant was the example of overwintering a poly mating nuc. We have done it with Apideas - definitely not what they were designed/intended for, but it is possible with very close attention, and they can be built into full colonies the next season. IMHO it's an academic exercise rather than a viable queen banking / insurance nuc approach.
I have done it during last 10 years and I have used 3 W electrict heathing. What I learned?
I started to over winter one box colonies. It is easier to make them during summer than get 3 frame colony to build up next spring.
Our winter is a little bit worse than yours. I have wintered 2 frames colonies during 10 years but they are not able to make brood after winter.
"and they can be built into full colonies the next season". That is not true.
Just colonies or productive colonies?
You may buy a queen outboards and make a split in spring, but it is not wise.
This spring I had several colonies where nosema dwindled away workers before they got new worker bees.
I took queen away and give new bees from healty hives.
When bigger hives got enough brood, I give frames of emerging brood.
But if I take from one hive 3 frames of brood off, its build up stops for long time.
Now, after one moth build up those hives have 2 boxes. They are not able to make honey this summer, unless at the beginning of July I join them to make productive colonies.
Dekemn says that he makes something new? Beeks have made the same for decades. There is nothing new in those experimenst and nothing academic.
As I said, you have in UK too small colonies without making them.
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