I apologize in advance if this question has been asked before - I searched for ages in the forum as I thought it would be covered but I can't find it so here goes.

I recently booked 2 return tickets YUL-SYD using 160000 aeroplan miles. I have over 350,000 to spend but couldnt for the life of me get a business class seat. Zero availability, I even spent 30 mins on the phone with a very helpful chap who checked EVERY flight from every west coast hub for me.

So here's my question - is it worth phoning every few weeks to see if anything opens up - am I even allowed to transform my economy reward ticket to a business class one (of course I'll burn the extra miles and whatever $ it needs)

thanks in advance for any help - I'm going to Sydney to run the marathon and need all the shuteye I can get.