Can't remember where, but IIRC they only operate at locations which can be reached from their distribution centers by a truck in the same day. I also recall that they recently opened another distribution center in Texas (which is why they are now opening locations there). So they are indeed expanding eastward, but it will probably be a while before they establish a presence on the east coast.
If I remember the article I read correctly, all restaurants must be within either 350 or 500 miles of a INO distribution center, and they only serve something like 50 per center (this from an article talking about them finally coming to Colorado with a distribution center and the first location down in the Springs, though Denver/Boulder have to be soon to follow).
