From Montreal Dorval Airport, getting into the city is a simple matter of either getting a cab, train, or hiring a car, and the city itself is easy to negotiate, and there is plenty that you can see on foot, although for shorter breaks it makes sense to use cabs and the excellent underground service as much as possible.
If you're planning to leave town a few times during your stay, then it makes a great deal of sense to arrange car hire in Montreal prior to travel in order to make touring Quebec more convenient.
