6 days is more than enough, I got an A+ on less time than that. Seriously, a decent cheat sheet can get you an A to A+ imo.
Do you have any tips for using the cheat sheet effectively during the exam? I'm constructing my cheatsheet now and it's looking pretty good, should I put some model answers and stuff it in? 
Yeah, mine (I uploaded it to the notes section, but it's handwritten and kinda hard to read to anyone but me haha) was packed with theory (which kinda had model answers in it), equations, graphs, etc.
For those who are under-prepared, the more of the course YOU (and this is important that you write it yourself imo) can cram into it the better you will be. Just try not to write it on the day of the exam, spend the time before the exam slamming as many VCAA exams as possible (that's what I did anyway, I had 3 hours lol).