16"s seems like a long distance to force the queen or the bees for that matter to travel. My advice is to cut the log down to the point where some of their comb is sticking 1/2 inch or so above the piece of plywood that you place on there. you can try to situate that piece so it's between 2 combs above or use a medium in place of a deep where it sticks up. 2nd I would make a top entrance to the hivebody you stuck on there and make this your only opening in the hive. This will force the bees to go through the deep you put on there to get out and eventually the queen will be encouraged to move up to this wonderful new space. Check the hive every week or so, when you see the queen (not just eggs, but the queen in the hive body), place a queen excluder on top of the plywood between the hivebody and the log. 4 weeks later remove the log and shazame you have all the brood in the top box and they will move honey and stuff up.
Rod
Rod