Generally, the chances for any OOS applicant to UNC-CH are somewhat problematic due to the highly competitive nature of OOS applications there: UNC-CH admits OOS applicants in numbers that are calculated not to exceed 18% of an entering freshman class. See “Undergraduate Admissions” on Page 2, here: http://www.admissions.unc.edu/files/2013/09/Admissions__Policy.pdf. Additionally, fines have been levied against UNC-CH in the recent past for exceeding the admissions cap for OOS admittees (at least if it happens 2 consecutive years: https://alumni.unc.edu/news/fine-okd-after-carolina-exceeds-admissions-cap-for-second-straight-year/). Because of these financial disincentives, I suspect that UNC-CH will be careful that it doesn’t exceed the 18% limit of OOS students in its entering first-year classes.
Further, over 2/3 of applications to UNC-CH for admission as a first-year student are from OOS applicants (29,563 OOS applicants out of 43,472 total applicants, here, https://uncnews.unc.edu/2018/08/17/carolina-welcomes-5095-new-undergraduate-students-to-campus/) ; so 68% of the first-year applicants are competing for 18% of the first-year slots. This disparity resulted in the entering Class of 2022 having a 13% acceptance rate for OOS applicants: https://uncnews.unc.edu/2018/08/17/carolina-welcomes-5095-new-undergraduate-students-to-campus/ (29,563 OOS applicants; 3,829 admits).
If you look at the UNC-CH Common Data Set, here, https://oira.unc.edu/files/2018/06/CDS_2017-2018_20180605.pdf , under Part C7 it states that standardized test scores, application essay(s), letter(s) of recommendation, and the rigor of your high school record are “very important” academic factors considered for freshman admission, whereas GPA and class rank are “important” academic factors considered for freshman admission. Extracurricular activities, talent, and character/personal qualities are considered as “very important” non-academic factors.
Further, Part C9 of the Common Data Set for UNC-CH gives the median 50% for both SAT and ACT scores, as well as the percentage of the entering first-year class falling within certain ranges of SAT and ACT scores; Part C11 gives the percentage of entering first-year students falling within a range of unweighted GPA on a 4.0 scale, and Part C12 gives the average high school GPA of first-year applicants.
By way of comparison, our OOS high school usually has 8-10 students who apply, and 1-2 students who are admitted, each year to UNC-CH; and, with the exception of legacy students, our admitted students have SAT scores of 1500+, ACT scores of 33+, and weighted GPAs of 4.4+. These successful applicants also were involved in extracurricular activities that showed commitment over time (no “drive-by” ECs), and demonstrated leadership in the school as well as their ECs. Other kids in our city who I know were admitted to UNC-CH recently also had similar academic statistics and non-academic characteristics; and all of these kids were “unhooked” in admissions parlance (i.e., not a recruited D-1 athlete, or a URM, first-generation college student, etc.).
I don’t know whether your high school has Naviance or any similar program that gives information about how students at your high school have done in applying to colleges and universities; if so, you might peruse that data. I agree with the poster above that your chances as an in-state applicant at U of M are much better than your chances as an OOS applicant at UNC-CH.