I can give you information concerning what is going on in France.
Aerial power lines inspections are almost exclusively done by RTE, a branch of the Electricite de France Group.
They operate cameras mounted in gimballs.
ThermoVision 1000 LW, with bi-focal lens.
This camera is a scanning model, but with an excellent spatial resolution.
I can not directly give any thermograms. send a request to firstname.lastname@example.org, and I will forward it.