Full pax, Easy! As a rough comparison...
BNE-LAX (6283nm) is 320nm further than JNB-SYD (5963nm). Todays BNE-LAX 789 flight left with all seats occupied, 7 tons of FR8 on top of pax bags and was planned to land in LAX with 2 hours EOD. Transpose the same AC and payload to the current conditions at JNB (17* and calm) and it can do it with a couple of tons to spare. If is was actually 30* in JNB, adjust for the fact that JNB SYD is 320 shorter than BNE-LAX, dont need 2 hours FOD, and lose the 7 ton of FR8. Still fits in OPT.