I’m sorry. That’s unfortunate. There are a lot of great non-Ivy League schools in Boston, NYC, Chicago and Philly. Some that offer very generous merit scholarships.
How hard are you and your GC working the wait list? have you made a strong commitment to Penn (or Columbia) that if you’re accepted, you would immediately accept the offer, forgoing your spot at Brown; and immediately withdraw your name from the waitlists at Yale, Columbia, Berkley etc…
With regard to Brown, if you are a double concentrator with comp sci, you won’t really have much of an open curriculum. You’ll have a lot of required classes.