Upgrading CO international fares
There doesn't seem to be a whole lot of concrete info on the CO website in terms of upgrading internationally. I'm going to be flying to Germany in the fall and I'm wondering what fare classes can be upgraded. I won't be buying a full fare ticket, so it will likely be a discounted fare class. What fare classes can be upgraded and how many points does it take one way? Does anyone have a clear understanding of this?