My two cents:
I auditioned at a school in North Carolina for performance on electric but ended up playing upright. I had never played upright before college. I had two tunes prepared, Vic Wooten's "The Vision" and "Classical Thump" both had my own endings/twists/Victor Wooten's playing circles around me in his sleep stuff. I had known those for a few years by that point, it just took some relearning. They listened to one song, had me sight read a line, and talked some music with me. SUPER laid back stuff.
As for my Grad school auditions: I prepared for weeks. I had three tunes ready. Jaco's Continuum, a Pablo Casals tune (Song for the Birds I think was the name), and I transcribed out NHOP's solo on Sometime Ago. This is NOT standard repertoire btw. They didn't have me audition!! This degree is for Music Ed w concentration in Jazz Studies. They asked many more questions about my Ed theories, likes dislikes, etc.
As far as the degrees, I'm glad I have them for the technical side of things. Jazz can get pretty formulaic, just keep trying to find ways to have fun with it. I've been playing along with my Jackson 5 greatest hits album I got for Christmas. Hope this helps! PM me if you have further Ed/jazz studies questions