1

Short answer....No, not outside Brazil.
Don't confuse "visa" with "prazo".
If you have a U.S.passport, you should have a 5 year multi-entry visa, or if it is more recently issued, maybe a 10 year multi-entry visa.
You should have been given a 90 day prazo (stay) on entry to Brazil. So (if I understand what you have written correctly) you should figure out how much of that you used up on the trip 2 months ago.That is what you have left to use in January. A couple of weeks short of when that runs out, go to the PF in Brazil, ask for an extention, usually of 90 more days (but discretionary), and pay the small fee for the extention. When your 180 days is totally up, you must stay out of Brazil for 6 months.
Hope that helps.
If your visa expired, you should be able to apply for a new one. even outside the U.S. (in Argentina, if your passport has sufficient time left on it), but there it may not be a 10 year multi-entry one (that you would get in the U.S. at the Br. Consulate that has jurisdiction over your residence there) and will cost the same fee.

2

Hey! Ok, I thought that too - that it was good for 5 or ten years, but it says it is valid for 90 days from the day i entered with a maximum of 180 days. i dont know if b/c i got it here in BA it is different? Does your visa say it is valid for 5 or ten years?

3

This is an example of the "new" 10 year multi-entry visa and how to read it.

http://www.passportvisasexpress.com/visa_services/brazil/country_information/how_to_read_your_visa

If you got your visa elsewhere (other than at the Brazilian Consulate has jurisdiction over your residence), it could indeed be for less time.

4

It might be informative for future reference to know which Consulate (what city) and when (date) you applied for this visa.