nothing is impossible. It has been done before if you look on the boards. However pounding out the OG and 2 prep tests will not get you there. You will probably need to do thousands of questions and spend at least 6 months of focused studying in my opinion. And depending on your skill level you still may not get there. GMAT's a b**th isn't it?? lol But if it were that easy to score a 700 it wouldn't be so highly valued.
So I suggest starting from the ground up. Learn all the rules cold. I suggest starting with Verbal and learning SC first. You need to address that 21V first and foremost. Get Manhattan SC. If you learn that book alone you can probably up that V score to 30 all else being equal.
Edit: One more note: You can probably get to 600 in 1 month of studying. 600 to 700 will be the biggest hurdle.