Eu apoio esse tema!!

Fabulous! My wife is a carioca, although we met in Salvador which has the second largest but arguably the best carnaval celebrations.
I visited Curitiba many years ago. Clean, leafy for a Brazilian city, distinctly chilly* in winter and somewhat dull. The FEB and Niemeyer Museums are definitely worth a visit though. A city that few people in Brazil would associate with carnaval, although the myth that it doesn't have one is just that, a myth. Strangely enough, in the real world, Curitiba has a homicide rate significantly higher than Rio these days. You'll have to introduce the relatively recent concept on the narco-evangélico into your games. It's as bizarre and scary as anything in fiction.
* Only time I've actually ever really needed a jacket in Brazil.