"Can man derive any personal benefit from living in a human society? Yes—if it is a human society. The two great values to be gained from social existence are: knowledge and trade. Man is the only species that can transmit and expand his store of knowledge from generation to generation; the knowledge potentially available to man is greater than any one man could begin to acquire in his own life-span; every man gains an incalculable benefit from the knowledge discovered by others. The second great benefit is the division of labor: it enables a man to devote his effort to a particular field of work and to trade with others who specialize in other fields. This form of cooperation allows all men who take part in it to achieve a greater knowledge, skill and productive return on their effort than they could achieve if each had to produce everything he needs, on a desert island or on a self-sustaining farm.

"But these very benefits indicate, delimit and define what kind of men can be of value to one another and in what kind of society: only rational, productive, independent men in a rational, productive, free society..." -- .Ayn Rand, "The Objectivist Ethics"

In the long run, self sufficiency means you have to produce everything that you need for your life, leaving little time for much other than supplying shelter and food.

But in the short run during the collapsing of a society, it could spell the difference between disaster and at least a semi-normal life.

I think an acre or two is a good size plot to allow for some agriculture (although hydroponics would produce more) , energy production, and defense over a 6-12 month period. Your own water supply would be essential also, or agriculture would not thrive.

Self sufficiency is relative. Each member of the Gulch relied on themselves to produce and trade. As their proficiency progressed their trade increased. We will all reach a level we are happy at. Where is yours? How do you define poverty? JG lived in a run down flat 11 months out of the year, but in my mind he was one of the richest n the planet for he was able to focus on that which meant the most to him.

Freedom to create also requires tolerance of others creativity.

Most do not require that. You must have very large elbows.

A 4 or 5 acre lot is good privacy for a house lot, but usually too expensive in urban or suburban areas.

40 or 50 acres is nice in rural areas to be able roam in privacy to your favorite spots.