Wire bottoms

[OPAVP]

Good day, I am trying to winter 2 hives with open(wire)bottoms.  I have a screen on a frame,the size of a super, below an empty super. Then next 2 brood supers. Food above. Should I have put in a couple of empty frames in the bottom box? So they can climb up?  Give me some ideas.
Cor Van Pelt. Alberta. Canada.

Top ventilation of  course!!