> Organising something like this in a controlled area like a campus must be a few orders of magnitude simpler than organising something like this across the US.

Not necessarily. When a new address comes up, a human operator might takes a look at a satellite image of the address and give the drone an appropriate location to land on the property. That data would then be stored. 15 seconds with a human, one time only, is all it would take to make this easy in most neighborhoods.