Do you know what type of engineering he is looking for? We have a pretty good and competitive department, and are actually pretty big on campus. A lot of money & attention goes to the Engineering and Business programs on campus, which are strongly promoted within the community. Size wise, he'll likely enjoy Boise. Once he gets on campus, he really doesn't need a vehicle, just a bicycle or long board. Climate isn't a big change, but a lot less pollen. If living on campus, he could be fishing 3 minutes from his dorm room.
Small world, my sister-in-law lives in VA and my niece and nephew both graduated from River. There are a bunch of kids from that area coming here. My nephew is a senior this year (Business). My niece would have come here too, but our soccer program isn't as well known as Portland, so she is playing as a freshman there in PDX as a Pilot.
I'll add more later, have a student in my office right now.
Tom
ETA***- Where are you staying? How much do you want to spend on dinner and what type of food are you looking for? Downtown, American food, I'd go to Fork, or Bittercreek Alehouse. What type of beer do you like? 10 Barrel is downtown too. So is St. Lawrence Gridiron. I wasn't overly wowed by the food, but Taphouse downtown on Main has plenty of beer as well. Bardenay is good too, but is basque/American.
Forgot to mention that all students get a little sticker for free bus pass too. There are tons of club sports and activities on campus, the Rec center is pretty nice too. I've heard the baseball club is good, but it's just that, a club sport, so they get very little funding from the university. However, they are trying to get the program started and hire a coach to start the recruiting process and get an official team going.
Unfortunately, I will be at a conference when you are here for the visit, or I would have tried to meet up with you.