If fiat collapsed tomorrow you would expect what? Murder, Looting, People setting random fires, full on riots.... Why though? There are enough resources outside my house right now for me to get food and water for myself. If the government stopped right now I really wouldn't worry about starving to death like Venezuela. I would worry about lazy assholes who would rather steal shit from me than go make it or hunt it themselves. Many of us subsist on steady diets of news media and political double speak without which our sanity will be lost. The worst thing that can happen is another superpower sees USA as being unable to coordinate a nuke strike because we all couldn't handle impeaching a few assholes and hiring better ones without turning into an episode of the Walking Dead.
The childish nature of (some) partaking in doomsday prepping is astonishing, If you get nuked chances are you wont make it inside your fancy nuke bunker just saying. Some people build houses in nuke bunkers, good thinking I say. But If you are that guy who thinks buying 27 guns means you are guaranteed to live through the carnage I say this to you. Bullets can kill a man with 100 guns on him. It's better to not get shot at in the first place. Don't forget that just because SHTF.