In the US, you can get an MRI pretty much immediately from one of many facilities. The wait time in Canada is pretty ridiculous, and far below the standard of care anyone should expect.
https://www.fraserinstitute.org/studies/waiting-your-turn-wa...
I've known people who moved to the US from Canada because they could not get adequate health care under the single payer system. Hospitals on the border with Canada routinely have to deal with the spill over from Canada because Canada's system does not have the capacity to deal with all of the cases (I have relatives in such hospitals who talk about this). Medical tourism to the US from Canada is one of the few options people have to get timely access to needed healthcare.
We already have an enormous amount of regulation and control of this area by the government and it is not working. Regulation can be like violence - its practitioners always seem to want to use more if it when it is not working. It's time to take a step or two back and reevaluate.
With single payer the government could also put together some emergency grants/funds for hospitals that can't cope -- as long as they accept auditing from the government of all their processes/administration salaries/etc.. and follow guidelines take pay cuts to recommended averages, etc...
TLDR; Medicare for all will solve this issue, it will need to set the low-end higher obviously to compensate for where hospitals make the bulk of their money, but it'll need to hold hospitals accountable for better money management, and pay structures, and price gouging. Not to mention one of the largest cost savings : single-bulk-payer for drug purchases.