I'm looking into a booking I want to make later this year for flights in 2015. The plan would be a YUL-Destination (few weeks stop) - Stopover 1 - Stopover 2 - YUL

Given that there would be a few weeks between the departure flight to my destination and then the return flights, I'm afraid that availability would book up on the departure flight before I can even book the return flights (including stopovers). So would I be allowed to book the departure flight as a one-way and then call Aeroplan when the return flights become available and book those. Worst case I can see with this setup is a $90 cancellation fee on the initial flight which I cancel and immediately rebook as the round trip.

Would possibly be a good idea to call Aeroplan and ask them about this first, though I'm not sure they have an official rule for this.