The lack of award space is unreal.
There is no space on UIO-IAH EVER apart from a couple days in Feb.
There is definitely something wrong here, because there arent even any CO Platinum access seats open.

There are some days in November, so maybe close in there is a better chance.

The only space available is on Copa (useless to Aeroplan)

btw, Air Canada to Brazil - all those fees - and on top of that a change fee for a Y ticket - ouch!