One acre is optimistic. A mainly vegetarian diet in less than ideal soil conditions (think raised bed gardens) would require about 2--3 acres per adult (10 acres/family of four/2 adults/2 kids under teen years).

Been there, done that. Above requirements include outbuildings, main dwelling, wellhouse, septic, pond, and fuel (scrub oak).
Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein