Regarding the government coming for the supplies of productive people, that’s exactly what happened in Venezuela. First, they took over the food production plants. Then they took the farmer’s crops. Finally, they made people register their backyard gardens and chickens. Piece by piece, they took over every means of production.
So it might be the best idea to make your personal production a bit more low-key. A couple of chickens “just for the family.” A few tomato plants, etc, etc. Year-round rotation gardening would be important as you created a just-in-time supply for your own family. I don’t think they’d bother with people who are just growing a few things at a time. I think they’d come after people with a couple of acres of food. (They meaning the government.)
Now as for hungry people, DF is right – they’re not going to be able to produce their own food, at least not initially. (If ever, but let’s give them the benefit of the doubt that they might try.) It’s possible these folks could end up in some kind of shelter or camp environment, barely subsisting. I could completely see the rich folks retreating far away from the rest of us.
I think it would be at the least, months down the road of an official economic collapse that things got to this point, if not years. The collapse of Venezuela began to become publicly visible back in 2013 when they proclaimed hoarding (prepping) illegal. Keep in mind that this is when the people started to notice things were going wrong. The government had confiscated the guns back in 2012, because they knew what was coming. So now it’s 6 years later and the place is virtually unsurvivable. But it didn’t happen overnight there and I doubt that it would happen overnight here either.