I'll throw another perspective on the table on top of what's been discussed already. You also have to think about matching. Getting in is one thing, but if you don't match, your MD is pretty much useless. From what i heard, matching into residency through CARMS is extremely hard if you did not graduate from a canadian med school. Maybe a canadian can shed a light on topic, but i just hear about how hard it is to get into residency in canada if you didnt go to med school in canada.
If your goals are to match in the US as a canadian, that poses another hurdle. The NRMP match favors US American medical graduates (AMGs) over IMGs. Then it gets even more complicated. If you're an IMG, you're split into two categories: US-IMG (those who are US citizen or green card holder/permanent resident) and non-US IMGs (pretty much everyone else aka not a US citizen/GC/PS). Some residencies don't support any visas, so it makes it harder to match as a canadian because your pool of residencies to apply to is lower due to that reason. This makes it "slightly" easier for US IMGs to match into US residencies as they don't really need a visa, but it's still a lot more difficult than US AMGs (MD/DO).
I'm at the big 3 and I'll throw this out there. I can say that there is a good portion of students who go to the Caribbeans think they have the same shot at competitive specialties or want to do them, like neurosurgery, ortho, derm, plastics, ENT, etc. Not saying, it's impossible to get into those competitive specialties, but it's hard and you have to really put yourself out there and find a physician-mentor who can talk for you behind the closed doors. It's already an uphill battle, and going into these fields, you have to be at the top of your game and even then, those PDs favor US grads more than IMGs.
The reality is that if you go to the caribbeans, you have to be 110% fine with doing primary care (internal med, family med, peds) at the core esp if one does not match into those competitive specialties( given that you have no red flags up to the point of Match). The majority match into IM/FM. Of course, other IMG friendly programs include EM, anaesthesiology, maybe path, but overall the primary care specialties are usually more IMG friendly. If you think you would be unhappy at any of these specialties, then I suggest you work hard now and try to get into a canadian or US med school.