Thanks. I did look at Sixt. Ironically, it was the EV that came up in their suggestion that prompted me to start this thread. :-)

I actually found a good price, booking through and airline's site. I don't have President's Circle with Hertz, To be honest, I wouldn't hire with them. They billed me £430 for damage which I noticed when I picked up the car, but unfortunately doesn't show on the video I took.