You’re a strong applicant, and should have a shot everywhere you apply. At the most competitive schools, the odds are against you as an unhooked applicant, regardless of the strength of your record.
If you’re seriously interested in the integration of CS+Design, it’s worth looking specifically for programs with strength in this blended area. The CS+Design combined major at Northeastern is terrific, and has both great co-op opportunities and also a student-led design studio that can be fantastic for building your portfolio. https://scout.camd.northeastern.edu/
Harvey Mudd is a terrific CS school, and the opportunities in Design have grown significantly over the past few years. The Hive Home - The Hive is the hub of design activity for the whole consortium, and Mudd’s Human-Centered Design curriculum is based there. Mudd students can also cross-register, seamlessly, for courses in the other Claremont Colleges’ art departments, such as the Digital Art sequence at Scripps.
The Cognitive Science department at UCSD is another hotbed of CS+Design activity.
RIT and DePaul are also known for crossover majors, and would likely be safeties for you.
In terms of “shooting the moon” with T20’s, I would think that the combination of Brown’s flexible curriculum with cross-registration at RISD would be hard to beat.
As for CMU… their Design program is fantastic, but when we toured, we found out that they really aren’t as supportive of the BXA majors as the university’s marketing would lead you to believe. They aren’t excited about dedicating studio space to people who are splitting their time rather than making design their primary major and focus. CS at CMU is devilishly difficult to get into. Definitely visit if you can; of all the schools I visited with two kids, this was the one that ended up being the least like what I expected from what I’d read online.
Good luck with the process; I’m sure you’ll do great - the important thing is to find the right fit so that you can pursue your passions without swimming upstream in a program that doesn’t encourage them.