Well the issue I have with that is i may get invite 9 months from now or even later, nobody really knows. It will be hard reading that book over and over again for months.Rigly68 said:Personal opinion: Don't try to reschedule because you think you might fail the test.
Suggestion: Start studying now, read the book and maybe keep doing the online tests once a week to keep what you learned fresh in your memory. Then once you receive test invite you are already somewhat prepared and can study a little more. With this strategy you should be fine with even just one week notice for test.