I agree with Hong Hu concerning the strategy, don't fix yourself a rigid strategy, just go there with the idea of answering all the questions.
For your strategy and to see if you feel comfortable you should first be able to answer most of the questions and then to do it on time (<2mn)
When you feel comfortable with this, you can take the test but don't be in a hurry. Also be logical with your schedule, if you want a GMAT result for early october, you can take some extra time now to continue your preparation (but still keeping some time for an extra emergency test in case of you got something disappointing). Up to you. But I actually believe in a long prearation, I really believe that you can score awesome score if you take something like 6 months but without doing it everyday 2h, just doing it regularly 1h for example...the problem for anybody is the available free time to do it