I see a “World Cyber War One” as a real possibility. It could leave a lot of the globe without power or communications in almost no time at all. Without firing an EMP nuke. Cyber enemies could cause our pipelines to jam or burst, our grid to collapse, our water plants to contaminate themselves, trains to derail, the list goes on and on.
I think this possibility is why the govn. is going to do a practice in November assuming the country grid goes down. It is the most likely scenario and could happen any day. Don't need a nuclear bomb, just stick some code in the right place and the grid goes down.
Your estimate of three days for stores to be cleaned out, is accurate or maybe it won't take that long in a panic. When a hurricane is going to come through here, after three days before the hurricane gets here, there is no food or water or gasoline to buy. In a panic, it might not take three days. Even when power comes back on, food on trucks can't get here until gas stations have gas as the trucks have to have access to gas to fill up after they get here in order to get back to where they came from.
The last item to get here after a hurricane is bread. Other foods get here but I suppose our bread comes from Houston bakeries and they had to gear up to make more bread to send it here. For whatever reason, bread took longer than other food to get here.
Flour, baking powder, baking soda (whichever one it calls for) will make several kinds of bread, the easiest being tortillas. Tortilla recipes are on the web and I have a recipe for the easiest way to make them; I should send you that.
Sorry the potato, white Sunflower tubers, and Walking Onions got on your thread but a bunch ask me for those websites and now they will have unending food so maybe I'm not sorry it came up here. Your story is about survival in the midst of a country meltdown and I do believe that happening is not far away.
You are a true Patriot.