I would keep an eye on fares, I watched for several months and finally found a sale on the Mileage Run Premium fare forum to JNB for 3200 CAD pp on an AC/LH/LX ticket. I flew YEG-YYC-FRA-JNB and back JNB-ZRH-YUL-YEG. All flights were amazing actually, and the lounge in ZRH was insane. Just keep an eye on fares, perhaps route from IAD-YYZ then onto FRA or ZRH and down to JNB. It'll be an amazing trip!!