Here's a better idea of the magnitude of the problem: There's some height on those trees!
I did snip this tonight: Did it despite dire, half-serious warnings from Tam, too. It worked out; I just sat a stepladder close, climbed up and took diagonal cutters to the poly line that connected the insulator to the stainless eyebolt* in the tree -- possibly not the safest thing I've ever done. You can't see it in the first photo but the wire was headed up across the roof peak, with room to spare.
* Recommended practice per tree experts. Supposedly less bothersome to the tree than having an earlobe pierced is to you, and much better than tying a rope around it. The tree, not your earlobe.