It’s a lot more than that. Even President Obama’s plan for “closing” Gitmo would really only be moving it to Illinois.
The detainees would be locked up there under pretty much the same legal conditions – meaning that they still wouldn’t be getting a full trial beyond the tribunals they’ve already had. (I’m not kidding; you can look it up.)
On the bright side, they wouldn’t be getting as much sun. That could mean more time for reading.