Leases seem like the worst aspect of this, at least a return flight is only half a month's rent (one would hope).

I agree that you are correct about this, even here in Boston we've just got so many colleges that even if the one I work at has no problems Boston in general seems likely to have a big enough uptick that it will impact everyone. That's a lot of students traveling here by plane all at once and even if they're quarantining when they arrive I bet their parents aren't...