Can’t think of any cons. But, pros on the other hand I have a lengthy list. Best thing would be you’d be able to experience Brasil to it’s fullest. The people open up to you and are happy your trying to communicate in their language. Most foreigners just try to get by with English or Spanish. You can go anywhere, do anything, and, get anything you want or need. Plus, no gringo prices.
So my advice is no matter how good or bad your Portuguese is… speak it! Only way you can learn is by doing it.