First suggestions

I think you should take at least 5 days to visit Buenos Aires, and a few more to to visit other places in Argentina.

Cordoba and Rosario (700km / 320km) are near and I could drive you for a weekend.

My family owns an apt in Pinamar (360kms from Buenos Aires), just in front of the beach, so that can also be a good option for the weekend.

The Patagonia is probably the most beautiful place to go but air fares and hotels can be expensive (probably around 250/300 dollars each).

If you decide to visit the Patagonia region, think about 4/5 extra days.

You can also take a day trip to Colonia (in Uruguay, accesibly by 2h-ferry). It´s a nice quiet town, with typical constructions from Spanish times.

If you fly to Rio de Janeiro, you should stay about 3 or 4 days, and an extra day to see the Carnival :) Carnival in Rio is awesome! I haven´t been to the Carnival but I know it can be pretty expensive. Besides, it´s summer in South America which means: high season, high prices everwhere. Anyway, even if you can´t make it for the Carnival, Rio is a nice city and it has beautiful beach towns all around it.
There is also a nice island just in front of Rio, with beautiful beaches: Ilha Grande.
Another great option is Buzios (around 360kms from Rio, accesible by bus), gorgeous beach town that is worth visiting it.

To sum up, if you want to visit both Brazil and Argentina, you should think about taking 2 weeks or so. The longer you stay the better you´ll get to know the places you visit!

Ideally, I would suggest you about a week in Buenos Aires + 4/5 days in other places in Argentina + 3/4 days in Rio + 2 days in a Brazilian beach town).

If you think this is too much, of course we can get rid of the extra cities and focus on the capitals.

Anyway, I will be updating this blog with more websites so that you can learn some more about the places I´m suggesting you.
No matter how many days you take, it would be so great to have you both here!

Needless to say, you can stay at my home, and I can help you find accomodation in other places.

Let me know how the Lufthansa booking goes!

I´m so excited!!!

Belen