I was waitlisted, and I think a part of it was a lack of demonstrated interest. I live a couple hours away, but just never got around to visiting, unfortunately. If I were to visit now, would it still count as demonstrated interest?
I doubt it. I would say write a letter to admissions, explaining that you still really want to go here, what you’ve been doing since you applied (any updates), and reasons you are a good fit for NU and NU is a good fit for you. Show them you actually want to go here and would go here if accepted off the waitlist, unlike students who treat waitlist as rejection.
That said, I would be cautious about wanting to go to a school you haven’t visited before. So visiting may be a good option–but you should do more to show interest.