To think of primary scenarios is a wrong way to think about it. We may not get blown to ash. But production of much of critical stuff[Food/Medicine/Sanitation] requires electricity these days. There is absolutely no way you are going mass produce and sustain food production for the level of population we have on earth, by using old stone age techniques. And this is first secondary effect. Food needs to transported, processed etc. How will all this happen without electricity?

Image what would happen if there is no electricity in the military. Which is such critical functions like that will get bulk of the available supply, leaving very little for everything else.

We may not go extinct, but given general shortage of food, struggle for resources and break down of law and order. The world will be a very different place.