Originally Posted by Pseudo Nim

Actually, alc's answer was exactly right, and it follows what I wrote earlier.

The *maximum* duration of your ticket can be exactly 1 year from the first flown flight. So in your example, this would not quite work that way: the right way to make it work is as follows:

* Dec 14, 2015: book travel for Dec 1, 2016 first flight, Dec 10, 2016 throwaway flight (but be careful... not many airlines release space that far ahead, so you need to make sure you actually have availability!)
* Leave your ticket in a drawer for a year.
* Fly the Dec 1, 2016 flight on that day, in a year from now.
* On landing, immediately call Aeroplan and reschedule the rest of the trip to end on Dec 1, 2017 or before (ENTIRE trip must be complete within 1 year of departure (maybe arrival) of the first flight).
* Find a way to get home by yourself from wherever flight #1 took you, hopefully not too far.