OP, I wouldn't take anything off the board just yet - even talking to a faculty adviser. If you have someone whom you trust and feel comfortable discussing this with, I would recommend getting their perspective. Only, though, if you feel comfortable with them.
As for actual recommendations: First, I would go have a glass of wine and celebrate that you have the choice. Next, I'd hope you'll visit Chicago before deciding - even bring your SO. Chicago is a great place and worth at least looking at (airfare will definitely be cheeper than a new round of apps...). You and your SO have to make the final call, but it might be easier if you make Chicago a reality first.
One word of caution about Chicago: You seem pretty interested in practical issues, Chicago does not have a stellar track-record of catering to those (though I have no clue what the South American History faculty is like). If this is a concern for you, look into how much you could draw on the Law School or Public Policy School's resources; they are much more praxis-oriented.
Just take your time and talk to everyone you trust about it. It is a great department, though, and a great city... And if it's any several friends of mind did the long-distance gig from Chicago and it has worked out for all of them so far, so it can be done.
Good luck!