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Walk away hive is pure nonsence. Really stupid to one hive owner.and you learn nothing from it.
So you want to have 3 hives next summer. That is wise and reaslistic idea.
The worst what you can do is to split in spring and destroy build up.
Second is split via swarm.
What i do and recommend to you is:
let the hive grow full size. In summer you take a frame on emerging brood. Then give food frame which has pollen and honey and then empty com or foundation.
What is a big problem : how to get drawn combs to this big fantasy? Andnext spring. To that you need a strong nectar foraging colony.
Then bye a laying queen.
Keep bees in a warm insulated nuc with normal frames.. let it bee 3 weeks and the nuc start to get its own workers.
Move the frames to 6 frame hive and take a frame of emerging bees again from big hive.
Now the nuc is quite strong and 4 frames brood.
You may make another nuc this way and let it build up.
When yield season is over, you may take from big hive capped brood and give to the nucs.
Now you have strong nucs which occupye a whole brood box.
These late summer brood are such that they do not work much and they will not winter,but they assist feeding nuc brood.
All these hives have power and time to make good winterers. Strong winterers are good spring builders.question is not only, do they go over winter alive.
When you want much bees, use douple brood.
But it depends, how good layer is your queen.