Providing abortion services for Americans does not cost us as they would have to pay.
However, IMHO OP's plan is silly and misguided. Most boarding states allow for abortion, and those that don't are closer to states that allow for abortion. The vast majority of states that restrict abortion are in the south, and the population who live under abortion restrictions are even more skewed south. This means even if people needing abortions wanted to come to Canada, they'd be more likely to enter at airports instead of land boarders.
Then you must hate our current universal healthcare as it is "for-profit". No one in the system is providing their services for free, they're paid by the Provincial Government (or in some cases the Federal government, like indigenous communities, military, etc). Some Doctors work as T4 employees, but the vast majority are in private practice where they bill the government for services rendered and operate as businesses. If the market demanded services at the boarder, businesses would be willing to provided their services without the government paying for infrastructure. Actually, I am currently seeing a specialist in a boarder city and the clinic advertises to Americans. They're more than happy to serve Canadians and bill the province, and the service has been exceptional.
I suspect your contentions with "for-profit" healthcare is the American system where regulation is minimal and the government isn't tasked with ensuring everyone gets healthcare? In Canada, for those without provincial healthcare, the provinces do have oversight on reasonable expenses .
Doesn't this solve our immigration problem? We can begin to import (presumably) highly educated people into the country who may be more comfortable living in somewhere that's not Vancouver/Toronto (given that they're coming from the US).
Canadian currently living in the US here. The problem is that these high skill jobs usually pays close to double in the US after taking forex into account. More than enough to pay for the extra cost for healthcare. Not to mention our healthcare system back home isn't in it's best shape at the moment. If some of these folks don't like their red state politics, they can easily move to a blue state instead of Canada where they're likely to get a massive pay cut.