Canoe outfitters in "remote" areas of Quebec are almost non-existent, you might be better off renting boats in Montreal.
On the other hand have a look at La Vérendrye, it's not extremely remote but there are a number of routes where you will see few if any people especially after the first portage. Gear / boats can be rented on site.
http://www.canot-camping.ca/home.htmlYou can also search this site for La Vérendrye, there are many older posts and many regulars have paddled there if you have questions.