I read on Wikipedia that they are going to show all 13 episodes, I think that means four left as of this writing and that the show producers got sufficient notice of the cancellation to "rework" the last show into a finale to "give the fans closure". Of course I realize that "I read it on Wikipedia" is only slightly more credible than "I heard it at the barber shop".
Thats been confirmed by a few of the people involved in the show, but how much resolution can you do in one hour? Whatever the existing plot line is in the 12th show is going to be wholesale dumped, and a completely arbitrary ending written for show 13. It's going to be jarring and likely make little sense.