Just finished CHS-EWR-HKG-SIN-HKG-ORD-CHS (well, technically still in ORD with rolling delays on CHS flight)
HKG-SIN - flight was half full, EWR-HKG was 2.5 hours late and they held it for roughly 20 of us on that flight
SIN-HKG - OMG - 8/8 in FC (Was booked 0/8 and everyone sitting there was on both the business and FC upgrade lists) 8 people sitting in Business and FA said 43 in economy
Those are rough numbers to continue that flight. FA did mention they fly this route often and weekends are packed, mid week is pretty bare - has seen as few as 14 people total on the plane