I think Jacobs might be a great fit for this actually. Eastman and Oberlin less so. And that is very direct faculty vibe we got there, so ask the hard questions as you visit. Eastman may allow you to take lessons at the conservatory a bit easier than Oberlin has however as a non performance major.
I will say the kids we know doing double degree are academic and intense. They are studying/practicing/in class just basically all the time. My kid has been studying through all his weekends so far. He had stats to apply anywhere. But we didn’t have an open pocketbook so we found a nice compromise of affordable/decent music/good academics. And an excellent single faculty member who really wanted him. He’s in a studio with 2/3 grad students which is an interesting opportunity too.