The Chicago Marathon is running on Sunday October 8, 2017 and could interrupt traffic for some considerable time.
By the end of the sessions on Sunday, most of the closer roads will be reopening.

Trains will be able to get you out no matter what, and those using cabs will be able to take several routes, which is shown
on the attached map.

The conference hotel is on Upper Wacker Drive, but going down the ramp behind the hotel lets you get to Lower Wacker Drive and gets you out of the loop, if you need to get through the closed roads earlier.

Going to the interstate to either leave, or get to either airport will be easy to do by session ending. Going north of the city will be easiest through Lake Shore Drive or the interstate.