It's been done, but you need a large enough drone to support the weight of the antennas and all that coax, as well as enough power to keep it running long enough.
There was a company at IWCE and/or APCO last year, they had a Ford F-350 with a generator/fuel/battery system and a large tethered drone. It would go up a few hundred feet and could carry repeaters, LTE radios, cameras, sensors, WiFi, etc. In the tether was fiber optic cable and power feed.
It would run as long as you fueled the generator.
Intended application was search and rescue, forest fires, temporary cell replacement, etc.