I'm trying to hold off until 1st November.
House is currently 17-18 degrees (midlands) so it's comfortable, but each degree decrease from here will be really noticeable...planning jumpers, blankets, hot water bottles and thick socks.
Also, what temperature do you keep your house at?
My electric use is around £80, on average, every month, but gas in the winter months got as high as £400 a month so trying to keep costs down.