I know some people say to take the outside frames in the lower box and move them to the center of the new box but I don't like that idea. Bees tend to build drone comb on the outside of the nest and I don't want drone comb right in the middle of the brood nest. So in your nice warm area I would just pull up the two center frames to the center of the new box and drop in two new frames of foundation in that space. Up where I live I would pull two frames from the center and then push the frames together adding a new frame to each outside space. If you are using foundationless they would have to go to the outside no matter what.
