I totally get it, I’m from NY, went to college in CT, but have lived in Seattle for 25 years and my kids don’t really understand the cultural (and weather/seasonal) differences between east, west, mid-west. There is always the chance we could visit in summer, but I do think it’s better if students are present on campus to get a better idea of “vibe.” It worked for me and D21 to go over her February break her junior year - she was shocked by the cold and brown landscape as she is used to more temperate and evergreen. She would have applied to two schools in MA anyway, but ended up getting in REA to Stanford and then saw no point to pursue other options.
For my D24, she’s not particularly invested in the process yet. She also has limited time off due to her sport. I would be dragging her to tour schools back east if we went this February. She doesn’t care all that much at this point, and I see no point in pushing her. Maybe a summer trip will happen, or maybe she’ll decide to stick with WA/OR/CA schools, or maybe she’ll apply to a few schools back east and then see where she’s admitted.
It’s a very different process this time but I am realizing D24 needs to be more invested if we are going to fly across the country (especially in winter). It sounds like your son is indeed invested, and I would do the same if I were in your shoes.