It's coming from the money we are currently paying for Healthcare, along with savings via better negotiating power with providers and lower administrative costs.
The US spends $3.5 Trillion dollars per year in Healthcare costs (and growing), most of that coming out of the pockets of our employers and ourselves.
Canada has waiting lists for some things it's true, it's not for things that are life threatening, like emergency surgery or cancer treatment, but for things like hip replacements, etc. I'd argue waiting is better than not being able to afford it at all. You'll notice they aren't exactly falling all over themselves to dismantle their current system and the let free market step in to "solve the problem."
Canada's population is also far less concentrated than our own, which leads to a lot of their problems.