Hi! Welcome to GMAT Club and Congrats on your admits!
Two different countries and different schools. Not sure where you would like to end up long term. There are a few angles/positions you can consider:
1. Do you have a strong resume? If yes, Canada employers often prefer a strong resume to a strong MBA. Even though Rotman is a top MBA program the volume of graduates and the small size of Canadian economy sometimes struggle to absorb all of the international students.
2. Have you researched STEM and Canada immigration rules? Which one do you prefer? Does Carlson have STEM?
3. What would give you a shot at consulting? Are you very good with clients? Would you impress a consulting recruiter?
4. Are you able to pay for your MBA or will you struggle with Rotman? If you have a hard time with Rotman Cost of living/Tuition, Carlson Free MBA is a great choice. Can't beat free
5. Are you OK settling in MN long term?
6. Are you a safe player or aggressive? Rotman is potentially more aggressive on the recruiting at a higher cost but better immigration policies. Carlson has a fairly small % of international students and that is a good thing in some sense for you. It seems to have a great track record with job placement (at least based on the official reports). So you may score a better job without much of MBA debt but you have only 1 shot at H1B (unless you get a job pre April, which is possible but i would not count on it) and to get STEM you will have to get the dual MBA/Masters degree which will cost additional $40K and half a year of your life to get the STEM OPT. This comes down a bit to luck/your aggressiveness in networking...
Worst Case: Carlson: you can get a free MBA and in the worst case go home with $20-40K in debt, which is manageable, esp after spending a year in the US and paying some of it off
Rotman: You end up with $100K in debt but likely to stay long term in Canada without dealing with H1B lottery. Pay is not as high for MBA's in Canada and job hunting is harder without a good resume but you will get there over time. Perhaps a better long-term outlook?
Lots of other variables too - where do you want to live long term? Do you plan to go back home? Do you have a family? etc.