2 B's and one C. Do I still have a shot for Northwestern, Columbia, etc.?

Still, extremely low, since most transfers are in the ~3.7+ range, and you can’t get anywhere close to that number. Note, however, the Columbia School of General Studies does like non-trads, but expect it to be full pay. Your best bet would be to transfer somewhere instate, ace the courses there, and then apply to NU or Columbia for a Masters.