To be honest, It shouldn't be too bad. Judging from your FLI, you've got at least your private, so avit102 will be a breeze for you... You'll only be flying the 112 course for that, which is only 8 lessons iirc, and basically gets you into the 'UND way of things'.
From then on, 221, 222, 323, 324 and 325 are really simple ground school courses that requires little to no studying. It may be a good option for you as you get your Commercial Muti Instrument at much lower hours in the 141 program when compared to a part 91 school.
Avit208 is a total joke of a class, a GPA booster, really. Atsc 110 and Atsc 231 are both really interesting classes, and really teaches you something.
Like middies10 said, 30credits are ~2 semesters worth of classes, But can easily be done if you just knock out one of the classes every semester. (2 avit classes in 1 semester for the 323/324)