Less people, more resources then. Having been born in rural Oklahoma in 1938, I know a little about hard times. However as many medications as I take to stay alive, I would last no more the 90 days. Even if you have resources, people will not politely starve like they did before, I can practically guarantee that.
No matter how fortified you are there will be little way to keep the hordes at bay, even well armed castles eventually fall. The good part is they will leave the well defense till last simply because there is lower hanging fruit, but eventual they will come for you.
The world I was born into doesn’t exist any longer.
If they are coming for you, take a few with you. ;)
That sadly, is the truth.