For a use case like this, I'd imagine that tethered multicopters could be a very nice fit. If you can just plug the base station into a power outlet, suddenly 24/7 doesn't seem that crazy.

PS: Apparently I'm not alone with this idea, search engine comes up with hits. https://elistair.com/ even have a tether kit you can plug into some DJI models (and others) instead of the conventional battery pack. Out of Lyon, France, nice!