The point of the "individual planning exercise" (or whatever) is not that you can spend from now until April planning it. It's about how do you react when set a task? Can you solve a problem, then make and execute a plan inside a deadline?
Similarly, for the earlier poster who wanted a 6 month head start on all the practical exercises during IOT. Each exercise period contains dozens of scenarios. How would he or she know which to prepare for? It would take weeks to make plans for every eventuality. Why not spend those weeks more productively, perhaps getting fit so your physical strength will increase and improve your resistance to fatigue, your mental ability and resolve.
Even before attending IOT, or even OASC, you need to demonstrate that you can prioritise and be as well prepared as possible. Worry about the stuff you can improve or prepare for, not that which you can't.
The closed book exams or short notice tasks are are just that - you won't know what is required until you get the briefing.