A single person or family with a stockpile of food and water won't survive. Once people know you have supplies, they will kill you for your stash. A family of 10 won't be able to hold off an armed mob of 100+ looking for food.

I read a story of someone from Bosnia during war and SHTF. He said the only people who survived lived with an extended family of 100+. That's the only way you can have the numbers to hold off people who wanted to rob and kill you. Friends who aren't blood relatives are useless during SHTF.

Ironically, the 3rd world solution of living with an extended family or clan is the only way to survive during a disaster.