Yes, basically, small towns will come together and function like a country. They will have sheriffs or law enforcement officers in charge of security...and they will guard the basics, like food and water. They will keep intruders out. Eventually most small towns will start trading supplies with eachother, they will develop their own currency. People will grow food, grains, and live off the land. It will return to more basic, simple life.
Hawk, I am not sure if we in today's society could survive, we only have to look back a hundred years to the Irish Potato Famine or the Russian Famine. Their skills could not save them.
You mention sowing and reaping grains, good idea but then what.? Do we know how to separate the grain from the shaft, where is a mill stone to grind the grain into flour.? Corn can be dried and pounded by hand into corn flour but that is a last ditch effort.
Who of us knows the good wild berry's from the poison ones, how many of us can milk a cow or goat.? Who can make a wooden plow share to hand pull through the ground to plant crops.?
Police to keep out strangers will be a must, who knows what diseases they may carry, back to ingrown society's that hate and fear anyone that is different from them.
On the other hand most society's could not have survived in the past without slaves to help them. The American Indian both North and South America had slaves or indentured servants. Spoils of war.
America at its early stages had Europe to trade with for blacksmiths to buy or trade for pre made anvils to make horse shoes, pots and pans nails and saw blades for lumber mills.
Doctors and dentists even if they take their tools with them will be unable to replace them when they wear out.
In the 1700's the very first milk cows came to this area from Europe.
We possibly could survive a year or 2 but when the toilet paper runs out we are shit out of luck.