What would you tell John Doe? SAT preparation.

Hello, I am an US dual citizen residing in Central America. I am somewhat worried for my SAT scores. I am applying to some IVY league schools. I am retaking the test on December 5, however, now that I started timing my practice tests, my scores seem to range around 1650, which is my current SAT score. This is frustrating because with just an extra ten minutes I can score 2100+ on the practice tests. What should I do to overcome this issue? If I score 1640 would I any admission chances at all assuming I have solid extracurricular activities and several “hooks”.

Very, very unlikely that an Ivy would consider you with scores in that range, regardless of hooks.