Normally, I would agree to accept the spring offer of admission, but, based on these particular schools, you need to be sure that the NESCAC school is a good fit.
Currently the NESCAC school is undergoing a transition from the ultimate preppy, rich white kids school to a more diversified student body. But the partying & drug scene still exists.
Both are urban schools, although Chicago is “more urban” than is Hartford.
What are you seeking in a college or university ? I ask because now is the time to work on transfer applications.
What do you want to study ?
Is the NESCAC school offering financial aid ?
P.S. Have you considered Connecticut College ?
University of Richmond for business & number of students (3,019 fulltime undergraduates).
Bucknell University & Colgate University.