You would get laughed out of the room if you limited your customer base to only those within commuting distance of your office, but for some reason with employees, the model is different? You want the broad market TAM but the local employee control.
Certainly, if you think you can hire in Brazil, why have you not attempted to do so yet? The only way for you to know for sure if this model would work is to attempt it. I do wonder if the US is going to begin to tariff goods coming in from outside of the country, if they will also start to look at offshore labor to penalize economically.