Well...it depends. The ones who live East most likely will die quite fast: to start with they don't speak Zombie...they speak French! and zombies hate French (well actually they hate everyone but is because we have issues) then the ones in the middle will die, first the 50% who live in Cities and the other 50% will die later on when we manage to find them...but they most likely die of boredom (what do they do there for entreatment?) and the ones near the West Coast, well they will probably survive because they hardly go out as they are so busy working to pay for their houses that are ridiculously expensive...those will die of exhaustion or wealth, whichever comes first...