Hi, I'm renting out my room from the 15th February until 9th March including over Carnival. It's in a lovely little house in Botafogo close to the metro and the bus stop at Shopping Rio Sul. The house has 3 rooms, a really big living space, a good-sized kitchen and garden.
It's available to rent for the whole time or separate weeks. If you're interested let me know as the cost will depend on how long you want it for and when (especially over Carnival!)
There are also other rooms free for staying over Carnival. Just for the week of Carnival it will be R$900 per person.