I really want to get a good score, so I'll be skimming through the course over the holidays.
What I mean by 'skimming' is not doing every single question from the textbook. In my opinion, it would be totally pointless to complete the course in summer when you'll be doing it again throughout the year. Work through the stuff and as you gain a grasp of the information, move on. This means you can have an idea of what's coming up ahead and it can give you a little more time at the end of the year to revise. If that's too much (it probably isn't), just skim through what you'll be doing in semester one. Then utilise the winter break to skim through the content in semester two.
Further Maths students are quite lucky because the course can be completed during the summer break, unlike most other subjects. It's quite an easy subject, but if you're unsure of a fair amount of the content, I'd probably recommend waiting until the year starts. In VCE, you need to do the best for you.