The UK has a similar system to Canada. Costs are controlled by controlling the funding. You set a cap to what you'll spend and let the system figure out how best to allocate those funds. It's a big reason why the cost per capita for healthcare is quite low - you simply choose not to spend more.
The demand for healthcare spending is almost infinite. You can set it up so everyone get an MRI the same day the doctor orders it. If you cut back and it takes a week for a non-urgent MRI is that a "proper" level of funding? How about waiting one month? Two months?
The truth is, a country needs to decide how much money they are willing to spend on healthcare. Some spend very little, some spend a lot. There is no "fully funded" system, only trade offs.