Maybe...but keep I mind that this (as pointed out earlier) is a very small thermal sensor - 160px x 120px. A small sensor paired with a narrow field of view helps - but as you mentioned, flying close is going to be the only way to get any significant detail. The OP did mention that they are just initially looking for anomalies on the lines or equipment and if one is found then they would send in better gear.
We have always used 640x512 XT cameras on power lines but the images were being analyzed later by someone who was not on scene with us.
I am trying to find a way to say yes, but really think we need to get out there and do some tests to confirm one way or another.
We have some public safety training going on this week and some mapping / survey training going on as well. I will make sure we find a way to look at some power line equipment with both a regular XT or XT2 and also an Enterprise Dual so we can compare specific items shots from equal distances. Or, if the field of view is substantially different, we will note how much closer or further away each camera is from the target and their distance or height relationship to each other.