My friend did it and it was a lot of work, but she was able to do it and she still was able to have a great time on her program. She took two Disney classes and two online classes through her school-she also recieved Internship credit, as her major required a summer internship for graduation. She really buckles down and got herself on a schedule and practiced good time management to get everything done. She did mention have a couple issues with being scheduled around her classes-which were not easily resolved, but she was able to find someone to cover for her. She did let her work supervisor know and it wasn't an issue after that, though.
So yeah, it's a lot of work, but doable. But first, make sure your University will accept the credits from the Disney classes, and that they will go towards the requirements for graduating within your major.