how far is too far for school visits?

A few things:

1) If the school is not too far, it’s worth visiting the place and arrange some discussions with current students via the recruiting team of each school
2) If the school is far just make sure you go through the official channel to arrange your visit so that it will be reported and inserted in your file, you want to leverage this to show your interest
3) If you apply for a school you need to visit it ! You’re talking about investing your next 2 years and $100k+ so I hardly see how you can’t spend a few hundreds to make these trips, I understand some don’t have the money but you need to borrow it or ask for a small loan...seriously it matters, and you can easily visit several schools located in the same area without too much travel.
4) I read on this thread that someone was trying to get in touch with current students and alumni to visit the school and have some discussions. I think alumni are usually a lot more responsive, current student are just too stressed and highly focused on their classes/recruiting. Try first with alumni and feel free to ask them if they know any current student available for discussions. To be honest alumni are a better source than current student, especially if you talk to someone who graduated 3-5 years ago, he will have a better vision of what worked and what didn’t work and he will be less complacent about his own school...