What if I transferred to UIUC?

I am currently a sophomore at Elmhurst College with a 4.0 GPA, a 29 ACT, and plenty of EC and leadership positions. I was looking to transfer to UIUC to major in accounting. If I were to transfer to UIUC (if I am admitted) as a junior, would I have to stay there for 3 years (due to their rigorous curriculum for business majors) or could I earn a bachelor’s in 2 years instead of staying an extra year. This may ultimately determine if I decide to attend the college as well since an extra year can be very costly. Thanks.