South America – October

We were originally thinking Fiji for our honeymoon but I then had a brainwave about 3 weeks in South America in early October 2025.

Would fly to Rio, 4/5 nights there then to Buzios for 10 or so nights then back to Rio to fly to Buenos Aires for 5 or so nights then fly back home.

Any opinions and thoughts on the idea? Any suggestions to do instead of the above?

Done loads of multi base trips (the states 3/4 times, Bali, Thailand, plenty of big European trips) in the past and never ventured to South America so was thinking it could be a potential option.

If there are 1000 other similar threads please tell me to explore those instead..