My Speculation:
Assuming this is an eastward route, and that TAR producers want to avoid Europe (including stopovers) as much as possible, perhaps teams will depart from South America and head to the Arabian Peninsula or Africa. From Sao Paulo, Rio or Buenos Aires, teams can fly direct to Dubai, Abu Dhabi and Doha in the Gulf, and Luanda, Addia Ababa, Casablanca and Johannesburg in Africa.
My speculation on countries that may be visited after Colombia: Guyana, Suriname and Uruguay