Those are incredible grades to achieve! it is great that you are aiming for such high grades.
I guess it all really depends on how confident you are in your ability to get those grades. If you have done any mocks yet that is a really helpful place to start to get an idea of what you are on track to achieve right now. If the gap is quite big, for example, if you achieved a 4 in your mock you know you really need to put in the work for that specific subject.
I think the best way to revise and not get overwhelmed with information overload is to do a little bit every day. Set 10 minutes a day to go through past paper questions. This will help you identify your weak spots; which you can then focus on the following day and master that skill.