Exactly, there's a lot of different ways to take this question. If you are talking about how far would your average low handicap/scratch golfer need to drive to just maintain a card, the answer would probably be 315+ yards of carry and extremely straight. But if we're talking about if you were to have an (PGA tour) average iron and short-game skill set, it would probably be around 265-270 yards, given you found a great number of fairways.
Something to remember is that amateurs and pros don't have the correlations between stats. For amateurs, how far someone can hit a 7 iron, or drive the golf ball, usually shows a pretty consistent correlation to how well they usually score. The Tour, however, is a much smaller sample size of the best players on the planet, and each of them is there for a reason. So although you would have somewhat of an advantage to be able to hit the long ball, it doesn't always translate to how good a given touring pro's scoring averages are.