I wouldn't go less than deep/medium. With a single alone I see all kinds of problems. Swarming of course. And, yes, there are ample cells in a deep for the queen to lay. What about honey and pollen? That will reduce the available cells. So all the honey goes above the excluder? Then in the fall you will be doing some heavy feeding....and where's the pollen stored for late winter/early spring use? And then there's what is called..."Isolation Starvation". Happens when a colony gets stuck on one side of the broodnest in cold winter, and starve with honey one comb away. With honey above, that doesn't happen. Then in spring, if the colonies are strong, you better get in high gear to get the bees sorted before they swarm. Just my opinion
Hi, I have been researching the single brood box concept. I would suggest you google "single brood box management". You will see videos that will help explain. The University of Guelph in Ontario has some interesting information. I plan on either using 1 deep or 1 deep and 1 medium for brood in a couple of hives to try this summer. The main difference with a single brood box is that as soon as the Queen starts to expand the hive it is necessary to install a Queen excluder and supers. This will allow the bees to expand to the top boxes and not be so crowded that the Queen decides to swarm. Another benefit is that there is only one deep box to inspect. According to one of the videos there are ample cells available in a single deep to allow the Queen to lay as many eggs as she wants. By the time the cells get anywhere near full there is emerging brood making room for new eggs.
As a side note, I have been using 3 deeps for several years, to insure that there was ample room and the Queen would not swarm (among other factors, slatted rack, ventilation collars etc). Last Summer I lost 2 hives to Small Hive Beetles, weak, smaller hives and I usually did not inspect the lowest box. Big mistake, the SHB took over and it was not good. Check out the Videos.