The 'connecting tunnels' is easy to implement ... I did this with mini-nucs overwintering in a greenhouse last year. I used 40mm diameter drainpipe but smaller would work just as well. It should be opaque to avoid confusion. It should also be flush to the outside wall ... I nailed a small separate landing board underneath each entrance and had entrances about 30 cm apart and there seemed to be little confusion or obvious signs of drifting. Make sure they slope downwards from the hive entrance to the outside to avoid driving rain causing a flood!

An additional advantage of an entrance tunnel is that, with a little ingenuity, it should be possible to block the exterior and interior 'ends' of the tunnel and so minimise bees escaping when moving hives. I lacked this ingenuity but intend to give it a bit more thought.

I used a glue gun to stick the drainpipe in place, semi-permanently attached to the building wall, allowing the hive to be moved as needed. The beauty of a full hive is that it's heavy enough to not move if accidentally knocked ... this doesn't apply to mini-nucs as I learned to my cost

Great pics Bridget ... like Bumble I'm suffering from shed envy.