I’ve been to England on several occasions. If you travel around in the fall or winter...what you tend to find is that the hotel/motel rooms are unheated until you check into the room...so it take an hour or two after you walk into the room for it to be “warm”. I doubt if it ever gets above 70 degrees, and most likely sits near 65 degrees for most of the time.
You tend to notice everyone is dressed in sweaters and wool. Most pubs are heated to the bare minimum. I think because of the enormous cost already for electricity or heat...they’ve done just about everything to just get by.
The British are a hearty people and probably could scrap by for a couple of days where power was only twelve hours a day, but they’d likely blame it on some political party in the end.
I lived in England for a while, I was cold the whole time I was there.