I'm surprised you a struggling too much with South America, especially if you are travelling around and therefore able to mix the availability of different cites. EZE looks to be the best bet. However if you are now looking for peak Jan-March 2018 dates it's bound to be mostly gone.

As has been said, a 241 to SYD is possible, booked at T-355 but it's not great value unless you're travelling peak dates (Christmas). A multi partner could be better.

If you don't have a better use for a 241, I actually think a 241 oneway to HKG, then a multi partner (20k miles, 240k avios pp in J) from there would be pretty good option. You don't make the most of the 241 but still save a decent 75-120k to HKG, then presumably the whole multi partner award benefits from HKG's YQ ban.

20k miles would get you lots of Aus flights and/or some spare legs/miles once you're home. e.g. hkg-bne-syd-mel-per-doh-lon-lca-lon.