U of I alum here, though from a few decades back. Yes, I had to live in either the dorms, or other university approved housing (fraternity, sorority, or private dorm), the first two years. My last two years, I lived in an apartment, off-campus but nearby, a closer walk to my classes than the dorm.
Anyway, when I lived in the dorms, my roommate and I soldered in our room, at my university-provided desk on the 3rd floor of Weston Hall. Didn't have much time to do that, and there wasn't much space, but I did so, anyway. When I was taking some EE classes, I could check out breadboards, ICs, and such, to work on assigned projects (but that's more likely to happen in your later years).
As for solder prohibitions, I wasn't aware of any, and I never even thought about it. Nobody seemed to notice or care. I know we weren't supposed to cook food in our rooms, but I wasn't cooking. Various people burned incense and other substances in their rooms, some of which were fragrant and illegal. A little bit of rosin flux, in the grand scheme of things, wouldn't be likely to cause a big issue. Of course, use ordinary precautions to avoid fire, but I don't think the risk is huge if you use a modicum of caution.
Anyway, there is not a lot of room in the dorms. But you can pack a few shoebox sized boxes of hobby things and store them in your closet somewhere. Take them out and work on your desk when you have a chance, and put them away when you're done.
As others have said, you aren't likely to have a lot of time for hobbies, but depending on your priorities, you can do some things. You may also have an opportunity to do some hobby electronics by joining IEEE, and/or working on a project for Engineering Open House. There will be no shortage of other like-minded people interested in EE, and projects to do. The problem will be setting priorities, keeping up with class work, and setting aside a little time for fun as well.