I'm surprised that no one has mentioned LAN, which is a transfer partner of SPG at 20:50 (SPG points:LAN kms). US-Brazil is 48k kms round trip, so your buddy can travel r/t to GIG for 20k SPG points.
The catch is that you have to fly exclusively on LAN metal, so this individual will have to get to either JFK, DFW, or MIA (or LAX, but that's presumably too far west) on their own dime.