//I was there, and apart from Ted Heath’s attempt to impose national blackouts (the three day week) as a stick to beat the miners (he failed) there weren’t any more power cuts than today//
I didn't read it in a comic. My dad and grandparents told me about it. Also the Winter of Discontent wasn't under Heath and, if you'll forgive me for saying so, does not sound like a particularly pleasant period to live through.
Like I say, I don't take the word of everyone who was alive at the time as gospel. It's perfectly possible for people to be wrong about the society in which they live in, let alone to misremember one from the past. But there's plenty of corroborating evidence to suggest to me that strikes and power cuts were considerably more commonplace in the 1970s than they are today.
Of course, you could make the argument I suppose that powercuts mattered less back then than they would now because people are far more reliant on electricity for entertainment/cooking/working than they were in the '70s, when TV was only on for a few hours every evening anyway, just about everyone cooked on gas, and the internet didn't exist.