New to Japanese learning. Been lurking this sub. Got inspired to do N4 (or maybe N5) this December. Is it possible?

Basically title. Gonna start studying this September, gonna study daily. My goal is to finish EVERYTHING in Genki 1 and 2, probbaly finish around September to November. Then start of December until the exam, gotta start preparing for the exam. I have a lot of free time since I’m not going to uni. Is it doable? I’m asking for your guys’ opinions. Thanks!