The basic question isn't, can you feed yourself now? The question is, could you do it if you had to?
It's said, by those who track these things, that the average big U.S. city could be self-sufficient for three days. After that, if outside aide wasn't available, the city would self-destruct.
Homesteading and return to the land movements have swept the U.S. and Canada is waves all through the second half of the 20th century. Mock castastrophe's---such as the fully-manufactured Y2K "crisis" have contributed to the desire for self-sufficiency. And we've learned a lot.
First off, the idea of self-sufficiency is laudable. But it's also an impossible dream if you mean to maintain your current standard of living. There are too many things you need that you cannot make yourself---or even barter for.
If you mean self-sufficiency on a late 19th-early 20th century level, then the answer is an absolute yes. It is very possible.
Next question: What will it take in terms of land, etc.? Although this really varies, the commonly accepted figure, to feed a family, is 5 acres. That assumes livestock as well as vegetable growing. For small, self-sufficient homesteads, "livestock" usually means fowl and goats, rather than, say, cows and horses. But, again, individual mileage may vary.
Many of us dream of self-sufficiency, or at least want that to be a goal. But how many of us actually prepare for it by learning the necessary skills. Quick, by a show of hands, how many of you could butcher a hog? Milk a cow? Put food by over an open fire?
It's one thing to grow a couple of tomato plants and a hill or two of beans. Quite another to grow enough food to mainatain a family for a year.
Anyway, family survival isn't all that hard. If you mean total survival, as in a real, global catastrophe, that's a different order of magnitude. You have to think, then, in terms of a life-boat community dedicated to survival of the species. Open question: How large a gene pool is necessary to assure that? And what skills, in addition to food production, would you want represented?
Ghee, Luc. Ain't you glad you brought it up.