Thanks Nathan,
The tiedowns are likely at Atlantic as that's where a lot of the Miegs folks ended up. My office will be at the south end of the loop (LaSalle and Jackson) so its convenient to reach by Metra if all else fails. I used to fly into DuPage with some frequency but the transportation between the rail station and the FBO was spotty at best.
I heard recently that there is a small contingent of non-Chicago resident SWA pilots who fly in and base out of Chicago. I'm going to try to find out what facilities they may have found.