A good plan, but unless you have QF Platinum status, precisely zero seats are available for F award inventory (from mid-December to mid-January) for trans-Pacific travel. I doubt QF will deviate from this policy, even for a new flight. It if just not possible to travel for free during Christmas on this route using EXP status. I've solved the problem (by earning QF Platinum after I had EXP). Or get them to fly out in March instead (Perth is still nice, some would say nicer than in December).