If this is the case, and you haven’t, you might look at Alabama.
You have over 50% OOS, with 2K kids from the NY/NJ/CT area, over 1500 from Illinois and over 1K from GA, TX, CA - and so many from all over so to your comment he would experience kids from all over the country - in one place. My son’s first year suitemate was from Scottsdale AZ.
Why - they buy kids like yours in - so it’s very inexpensive for smart kids - and your outcome will like not be dissimilar to NC State. My son has a job where he is in a program with kids from MIchigan and Purdue and Washington and next year Ga Tech and CP SLO - but also Bama, Auburn, Utah and even West Michigan or Akron.
My son personally chose it over other schools including NC State - which he wasn’t a fan of after we visited due to the separate engineering campus.
Hopefully you can work with what you have but if it’s living with people from other areas - you still have opportunities at fine - and inexpensive schools. Within engineering, you’ll have the same opportunities for most jobs from most schools. My kid had 20 interviews and mostly at nationwide jobs - including one offer from a Raleigh area firm ABB - so you still have options.