Radioflash (SF movie trailer).

In the SF disaster film Radioflash, when a nuclear device detonated high about the USA causes a ‘coldbringer’ EMP pulse which fries the power and electronics of North America, civilisation rapidly collapses towards a new dark age, and a family have to flee for the mountain safety of their crazy grandfather living off the grid, survivalist fashion.

I hope he gets to say, ‘I told you so!’