You have forgotten about core and distribution classes. And even in your major, there can be some classes that just aren’t your cup of tea… I just think sometimes posters about here forget about the WORK part of college… it is easy to get caught up in the more exciting and fun parts of the process. I would go back to college in a minute if I didn’t have to actually take classes! 
Op,
Sounds like true senioritis. Happened to my dd as well. Was accepted SCEA to a top 5 college. Then felt burnt out and grades plummeted. I did not address any grade issues except to say that should get B- or higher or offer may be rescinded (because I knew that she would be able to raise grades as needed). Dd Was organizing a gap year which we fully supported and encouraged. In the end, changed mind again and started college. After frosh yr in college, took a semester off (and did internships) and it reinvigorated dd. Had a better attitude when returned to college.
It’s senioritis. Happened to my first DS, whose grades were horrendous last semester in H.S. i was almost worried they would rescind his offer. My current Sr. is experiencing the same thing, but not as bad. He still wants good grades, but comments he’s just ready to graduate. It’s hard to stay motiviated at this point…they’ve done the work, got into the school, trying to get thru winter and everything is just the same old same old. You’ll see spark again in May, with grad around the corner.
As far as lodging for admitted students days… it would be best if he can arrange for housing in a dorm with a current student. Check with the admissions people about that. The twin cities is very large and has very diverse neighborhoods, not all save. Depends on the school. Also, if he is under 18 he may not be able to get a hotel room by himself.
Sorry. I meant “safe” on the previous post. Can’t seem to edit that post.
My older daughter went through something similar at the end of her senior year. I got concerned because she seemed to be retreating to her room to play WoW more and more, and then she said she thought she might pass on going to college and instead move to Texas to meet someone she played WoW with. It was worrying, for sure! But we arranged for a very special graduation present (sent her to stay with relatives in Ireland for the summer) and that seemed to get her out of her funk, and she happily went off to college in the fall.