I can speak to the three east coast options I’ve attended - can’t comment on Chicago but it might be further than you want to go. Unfortunaly Vermont will be out, as they only offer tent stalls, if you want permanent stabling. They have a beautiful property and nice offerings, and Albany airport is about 1.5 hour drive. It’s a beautiful drive, too. The town is really cute, and has a lot of charm. A lot of Mid Atlantic barns go here to beat the heat in the summer, actually!
HITS in Va actually has made a myriad of improvements since the mid 2000s when it was god awful. Permanent barns with mats, plentiful riding around the grounds with trees, upgraded footing in some of the main rings with improvements on the way. Your young jumpers classes will go in the GP and the footing is lovely there. You can fly in to Charlottesville but closest major airport is probably Dulles and then a 1 hour ish drive. July and August dates can be hotter than hades, though, so - beware. Summer in VA can be high 90s and crazy humidity.
saugerties is lovely, as well - it’s a large show grounds with tons of space but permanent stalls go fast, and they’re expensive $450 for the week IIRC. Otherwise you’re stuck in 10x10 tent stalls. They only have like, 15 paddocks available too so they’re hard to come by but, it’s popular for a reason. bigger classes and draws a bigger crowd especially during the FEI weeks so Vermont or VA will give you a quieter vibe depending on what you’re going for.