I would rethink “too close” for a 17 year old on medication. You don’t have to pop in once a week to do her laundry (and you need to reassure her that you won’t) but being able to get to her in an hour/two hours by jumping in your car is going to be huge if there’s an emergency.
If I read your post correctly, she has been managing her meds for less than two years, correct? College is a huge adjustment. I’d be looking at schools within a two hour drive. What does her therapist say?