I was checking on availability for some properties in Sydney between Christmas and New Years and the CP Parramatta still showed as taking bookings on the ICGH site, albeit was sold out for some of the nights I was looking for.

(Also, for what it's worth, on New Years Eve the only property close in having a vacancy was the SYD HI. Rooms are going for $600 a night, unless you wanted to use Pts&$s where the same rooms could be had to 15K and $60!)