I found QF F space on 12/22 heading down from LAX to SYD - but wasn't able to find anything coming back the weekend of the 5th (1/5, 1/4, 1/3..etc.) I ended up doing Fiji from AKL -> NAN -> HNL -> SEA, which is kind of a big PITA, but the dateline let me break up the flights and spend a day in Fiji, which will be fun - and still get in around the time I needed to be in by. And yes, QF blocked SYD -> AKL the last week of the year, so I booked an award flight via Avios on BA...which itself was a LATAM codeshare (??)

Long story short, Alaska has enough partners in that region to make it possible if you're up for doing some interesting routings. It might take a few more miles and some weird redemptions, but it's possible!