If the bees are on a flow and they are as strong as you say, I think you could do a walkaway split. I would leave the medium on the original location and put the deep on a new bottom board right next to it. If the boxes are both full, I would add another box to each and move a frame of brood up in the middle and put a frame of foundation in its place in the bottom box.
If you want to possibly get a honey crop, you need to open up that brood nest. That top half of the medium solid honey is telling your bees they can swarm now if they want. We have long fairly intense flows and here I might just put a deep with drawn comb or foundation in the middle. If your weather can go back cold, that is not a good idea. I wouldn't do that before June here.
Just what I might do. Hopefully someone local to you will give you advice too. What could I know? I live where the ground is still frozen!