I’m going to suggest an alternative approach that, admittedly, makes certain assumptions about your financial situation.
For several reasons, I don’t think the trip you are suggesting is likely to be as helpful as you want it to be. First, one of the most useful things you can do on a college visit to figure out if you like the place is to see it when school is in session so you can talk to students and get a feel for the atmosphere. You won’t be able to do that during this trip. To the extent there are kids there, it will likely mostly be high school students attending programs, many not even run by the college. I know of two on the Yale campus, right off the top of my head. Talking to those kids won’t tell your son anything about what it’s like to be a Yale student.
Second, I imagine that by the middle or end of the “If it’s Tuesday, it must be Belgium” whirlwind colleges tour, they’re all going to start to blend together and you’ll be left with only the most superficial of impressions, wondering whether that great view or big hill was at Amherst, Williams or Dartmouth.
Your son will see Yale because, apparently, he’ll be on campus, so if he’s never been on one before, he’ll get a bit of a sense of what being at a college is like.
If more leisurely trips to the east coast during the school year aren’t practical (and why would they be?), do lots of research on-line and using books. Use CC, The Fiske Guide and other resources to get a sense of the personality and atmosphere of the schools. If your son wants to apply ED to something on this list, narrow it down to a much smaller handful of schools and get him out here (I’m in NY, so here is the east coast) to do more extended visits at one or two schools. I wouldn’t let my kid apply ED to a school he hadn’t spent some real time at, preferably an overnight.
After the acceptances are in, if he’s choosing among some east coast schools, then he can come out and see just the schools in the running, when the school is in session and when he’ll have more than a minute and a half on each campus. Take the money you would spend on your airfare (if he’d otherwise fly home from Yale on his own), transportation, hotels, etc and use it to help fund the trip(s) that will be more useful for making informed decisions.