It would be über convenient if one could setup call forwarding to a Canadian number and/or cancel it via self serve. In my case I could call forward to a Voip provider in Canada that would then call forward to an overseas number at a low per minute rate.
That would be a lot of work, if do-able. Koodo probably doesn't have enough customers who call forward enough to implement the time and especially money into something like this. Remember that it's a lot easier to suggest an idea than actually think about what it takes to do it.
What's the problem with setting it up before you leave Canada?