A 6ft wingspan fixed wing "drone" is easy enough to build for several hours of flight endurance. It won't be able to exactly hover, but it could fly circles at slow speed, making the impression of barely moving if positioned high enough up.

I bet hovering meant a tight circle and those are winged (or maybe even blimps)

Right? At that point you’re trading off between useful payload and batteries. I’m wondering if maybe they’re witnessing a loiter pattern, and misrepresenting is as a hover. These likely aren’t aerospace Engineers giving quotes here.

A 6ft fixed wing drone could fairly easily achieve what’s described in the article if it was really a loiter, not a hover. A multirotor would be an engineering feat.

30 ft wingspan powered glider drone made from composite materials would be even more energy-efficient. Multirotor drones have low energy densities and waste it rapidly.

Other aspects to consider are that the “drones” are replaced by others as batteries deplete or that the drones aren’t really there as long as people believe.

It’s possible that someone is doing this as a hobby for artistic, conspiracy theory “reconnaissance“ or benign data gathering-purposes or conducting some sort of investigation or intelligence gathering.