AAAH!
Ok, so I've figured out something of a workaround this problem for now.
University results for each semester are released at some point (I keep forgetting to check the time) each Monday. So I rotate between households early on a Monday morning (usually around 3am when all the household members should be home). When I come back to my uni household, even though I haven't played them for around 10 sim weeks by this time, their grades come out at some point on Monday, they re-enrol and we continue with their merry studies until 3am the next Monday. If I stuff up and the grades come out before I've swapped over, I'll have to babysit them for another week. Haven't stuffed up the rotation yet but never underestimate my ability to lose track of time.
It goes like this:
Uni House - join them 3am Monday morning, if they're new they start their classes on the Tuesday. If they're continuing they get their grades and an opportunity to re-enrol. If you don't re-enrol straight away they lose whatever scholarships they had on admission, even if you then re-enrol them later. They then start their next semester on the Tuesday and away we go. Classes, homework, term papers, presentations, blah blah blah.
3am Monday - SWITCH! Go through the other families, then come back. They get their grades and re-enrol.
Rinse, repeat.
Something vaguely related I want to complain about: Playing on a dorm lot is strictly worse than playing on any other lot because running (or even biking) to class buildings takes longer than disappearing on the sidewalk.
Also, YES, this sucks. I've simply kept some sims living in the family home to study to avoid this. College experience? WHAT COLLEGE EXPERIENCE!? IT'S A PANDEMIC DAMMIT. STAY HOME. Pixellated brats.