Here is the [past enrollment data](https://www.berkeleytime.com/enrollment/?course1=4470-fall-2016-all&course2=2321-fall-2016-all&course3=2325-fall-2016-all&course4=2327-fall-2016-all). You can use it to gauge how affected you would be as a non-premajor. The waitlist numbers are a little scary and you might have to add other, less desired courses until other people drop / new sections are opened up to accommodate you.
Also here is a visual look at what you might be seeing in the Fall:
https://www.reddit[dot]com/r/berkeley/comments/4zfcnj/cs61a_in_zellerbach_hall/