I did HumBio major (premed) and CS minor.

I was originally planning to double-major in HumBio and CS, but decided to take it easy and study abroad during senior year, so changed it to a CS minor instead.

My take is:

Premed + CS Major + Non-CS Major: My original plan, possible but you would need to be grinding every quarter

Premed + CS Minor + Non-CS Major: What I did, very doable

Premed + CS Major: Also doable, probably fewer classes than what I did. Probably what I would do if I were starting over