Keep adding frames of food and brood slowly to help build them.
the the value of swarm has only the value of queen. And what is the value of that queen.
So you sacrifice the brood frames 4-5 pieces for that unknown queen.
That means that you make a split. The swarm is same size what I use as mating nucs.
Just now I have 15 extra queen. Lots of mating nucs.
I join hives before winter andnever split.
But Anette, your winter is not real and perhaps your bee summer continues there.