Hey Adam
A good question. It isn't recommended that you overload yourself with extra courses, because you'll want to not get overwhelmed or have so many projects on the go that it gets hard to handle them all. Your stress level will be through the roof!
However, it IS possible to do, but requires permission and a certain average to do so.
A
similar question was asked in the forums, and one of the MI staff, Jeremy, found this quote from McMaster:
"
Overload Work: If you wish to take more than the normal number of units prescribed for a Level, you may do so only with the permission of the Office of the Associate Dean of your Faculty. Normally, a Sessional Average of at least 7.0 in the immediately preceding review period will be required if an overload is to be permitted. Additional academic fees will be assessed for overload work."