I would try to keep the brood somewhat consolidated at this point. Try moving 2 frames of brood up to the center of the new box, and push all the frames of brood in the lower box together, centered under the brood frames above. Put all the undrawn frames on each side in both boxes and let them expand outward for a while. It might be just a bit too early to open up the brood nest too much. That's my take on it, FWIW.