Unfortunately those are really only bushes and not nearly tall enough. What are the tallest trees you have take pics, pm me if you want, ideally I'd like the see pics of the whole property.
The insulation on those cables is pretty thick, they wouldn't be wrapped around each other if not. I'd be a lot more worried about the other line which could be 10 Kva. You don't want to go near that under any circumstances.
You may want to install a mast of some sort, a 40 foot mast, of some sort, get scaffolding poles but they'd need to be guyed.
Anyway hard to know what you can do without pics of the whole property.
The High Voltage line is running high above the house, but more to the front, so I don't think we would be going anywhere near it to be honest.
Or my other option, if everything else fails, is to install a seperate antenna for 80m and leave the one I have for 40m upwards?