Probably, it'll be more like the fall of the Roman empire; a slow gradual process of increasing instability, culminating not in utter chaos, anarchy and apocalypse, but in finding a new (temporary) period of some stability.

It's probably going to be a decrease in quality of life for many people, but certainly not a cavemen fighting with sticks situation, and the bunker survivors gloriously emerging to rule the wasteland as kings, as some preppers seem to believe.