In less than 10 days, we start LAX-LHR(stopover for 3 days)-CPT and return JNB-LHR-LAX as a 2-4-1.. We booked 11 months in advance and yes the taxes were high but so what...its over 24 hours of flying in F. On JNB-LHR segment we have 4 F reward seats.

The seats were wide open for a couple of months after we booked.

It can be done, just need to book early and flexibility in dates helps.