AC has dropped GIG and only flies to GRU, and that's on a 787. Thus a significant reduction of capacity. You may have to settle for flying to EZE, buying revenue seats into/back from GIG. (Have you even tried GRU and buying local flights to SDU?) I was able to get a biz seat on AC from GRU-YYZ for January, albeit booked it back in July as part of a CPT-JNB-GRU-YYZ award on SAA and AC.