As you would understand, that is a tricky time to book flights especially on award flights.
Availabilities aside, the taxes/points payable are as follows (from random searches):
Krisflyer (SIA): $479.50 (63750 pts)
Velocity (SIA): $159.30 (112000 pts)
Qantas (Jetstar): $134 (57600 pts) (I couldn’t check for sure as I have insufficient pts =D)
Seems like Qantas is the way to go if you really want to use your points. However, only available date closest to before Xmas was 20 Dec. Krisflyer – you have to waitlist. Velocity – you have to pay a high premium in points as the saver-type rewards seemed to have depleted.
Do a quick search on comparison/ travel sites like Skyscanner, etc. if you wish to pay for the flights. You might find shorter transit times and cheaper flights compared to Garuda (nearly 24 hrs one way travel time from Sydney – very painful IMHO). Jetstar fly direct and is cheaper (approx $1211).
My 2 cents is to pay for the flights and use the points for future travels. But hey that’s just me. Good luck.