As far as I know, I don't believe we have to worry as much about SHB in New Hampshire? Only my first year so I'd need other NH beeks to confirm that but I haven't seen any here. I think it's one of the trade offs due to our harsh winters.
But great points about the slots being very small for getting your hand in.
Does anyone see problems with how small the clusters would be? For example if I took a 10 frame box and divided it into 5 two-frame colonies and tried over wintering that