Funnily enough, they were round surveying the line yesterday. Didn't notice a problem. Looking at them now, they aren't a million miles away. There's a storm damaged one out of frame that's much closer.
Don't want to kill the willows, though, isn't it best to cut them in the winter? They're coming into leaf now
To be honest, you'll have a hard job to kill a Willow, but you're right it's best to do the work late Autumn as a general rule. However, no tree surgeon or powerline company is going to down tools for 6 months of the year. In my experience they all survive.
The reason why they didn't see a problem is because there's still so much storm work and network in worse condition to deal with it has to take priority. Do be careful though, it's not like getting a shock off a light socket, the 11,000v has a live zone of up to 1.5m. If it's wet, foggy, or smoky then arcing is possible. Smoke is the worst because of the carbon and moisture combined.
No need to get too worried, but that sort of voltage needs awareness and respect.