Like many other places paranoid about terorrism, CDG doesn't have left luggage services.
You can use the lockers at any Paris train station, or if you really want something close to CDG, some of the airport hotels provide left luggage services. However, at a month and a half, you're probably looking at a pretty stiff bill - so it might just be worth going those two hours to get your stuff.
There are also self-storage options (like Public Storage in the states) cropping up around France. Companies include Shurgard,Une Piece en Plus, and Homebox.
Or there's the option of having your suitcase shipped - literally - back to Canada. Sending stuff by ship is slow and cheap, but it should be back home by the time you're done traveling.