Your "huge supersonic drone" is in reality a subsonic one, that's smaller than an F16 and flies no higher than 19,700ft while a typical airliner cruises at 35,000 to 41,000ft
It is huge by drones standards. It shows that it is easy to miss a missile or a plane in the air there. Russia attacked targets 20 km from Poland border. It is just a bit more than a minute of flying of a transonic plane and even less for a high-speed missile. 60-80 km is inside a normal combat range for S-300 air-defense system. The point is that 45 miles from the border you can still easily happen to step into a combat zone and get into a path of a plane running and maneuvering away from a missile or a missile chasing or even lost/reacquired target. The next link illustrates dangers of flying even 300 kilometers away from firing air-defense systems even during the peace time https://en.wikipedia.org/wiki/Siberia_Airlines_Flight_1812
