Okay, scratch Familia--I had completely forgotten about his history (it's not hard to overlook someone who just played for the Mets and A's).
But I highly doubt that Robertson would refuse to consider the Cubs just because he prefers to play in the Northeast. There's also Joakim Soria, who has plenty of closing experience (including 16 saves last year) and has two consecutive years of almost 2 fWAR. And if you want to take a chance on a rebound candidate, why not try Cody Allen, who has at least been healthy?
There's also the trade market. Will Smith almost certainly will be traded. And as the Goldschmidt trade showed, there's a limit on the quality of return for a one year player. Archie Bradley is another late inning option if the Cubs want to try to find a multi-year solution, though he'd cost a lot in a trade.