I live in Toronto and I've been wholesaling in the GTA since 2008. I've done many wholesale deals... and yes I've assigned those contracts. I started with wholesaling... now I also do fix & flips, hold rental properties and I've done a few rent to owns.
You do need skills in sales and marketing. (ie. if you don't have the skills then it's up to you to learn, grow and do!)
If you're not a millionaire and you're just starting out (like I was years ago), then find a millionaire or two (or more) who want to buy properties. Then advertise, send letters, door knock, etc to find the type of properties that the millionaire buyers want. If you find properties in the GTA, then I'll be your buyer. I usually have several reno projects on the go at any given time... fix & flips, or properties I reno, refinance and rent.
These days there are a bunch of people teaching wholesaling online... youtube, podcasts, etc. So its easy to learn the basics. There are plenty of people wholesaling successfully in Ontario. I'm still wholesaling deals regularly to investors who want either fix and flips or rental properties.