Thanks woodslinger - excellent resource. I'm totally out of my depth there, but everyone has to start somewhere, huh.
Thanks lumberjack - your videos are amazing - you obviously know what you are doing. Of course, you're right - it would suck in many ways, but be a bonus for a few.
Pros for me:
Possibility to inspect TIP (if using live camera).
Possible method for gaining isolation at TIP (if wanted).
Cons
Cold (battery depletion)
Wind
Possible damage to drone from tree/foliage.
Possible damage to property.
Possibility of drone getting stuck/lost and having to retrieve it.
Friction from line being set.
I'm still going to pursue the idea though. This video gives me hope (and is the first video I've seen of a drone doing this).
https://www.youtube.com/watch?v=io4YPV364RM
Found another couple
https://www.youtube.com/watch?v=uhZi9lt3YFA
https://www.youtube.com/watch?v=eIYuVATAXxI
Ideally for a line setting purpose we'd look for compact, protected (from rotors), precise, and a bit of power. I know you can spend thousands on these things (in reality - that's probably what it would cost).