It's kind of a 'how long is a piece of string' question. You could probably do it on 2-3 acres but you're going to be making sacrifices that you wouldn't need

It's kind of a 'how long is a piece of string' question. You could probably do it on 2-3 acres but you're going to be making sacrifices that you wouldn't need to if you had 10-20. The typical term is 'homesteading' and there are tons of resources for it. My aunt does it and is part of a collective and it's nearly a full time job.