Your new race schedule looks good! Good luck! I'm glad you're picking Chicago as your next BQ attempt, and of course in typical DB fashion, you've already looked at the weather data! Impressive! I think that if (and that's a big if) the weather cooperates, it can definitely be a fast course, and they've got 3:00, 3:05, and 3:10 pacers available to assist you. It's interesting that they changed the qualifier standards for 2018 - I had not known that! You'll likely get A or B corral with your qualifying time (I was in B but sneaked into C right after the gun went off), and while those corrals are smaller, you'll still have some crowding issues, but just for the first 3-4 miles. After that, you should be fine. Organizational support is excellent and the random weather is the only real negative about the race.
As for hotel recommendations, we got an AirBnB out in Bridgeport, which was charming and inexpensive, at least compared to all the hotel options. That may or may not work for you, depending on your needs. We used CTA exclusively to get around, and it was fine. Chicago's a cool city and your whole family should enjoy the Aquarium. Can't wait to see how the race goes for you! Definitely hoping the temps are cool and you crush it!