Note,
https://services.aircanada.com/eupgw...vice/eupgrade/ has a preview feature, which will tell your the timelines, eUps & cash required, for a particular route. Same info as the chart, but actually customized to the route you are interested in.
Also, to temper any enthusiasm you may have, at 25k you an only request 4 days out (mostly, rewards flights are 1 day, crazy expensive buckets are any time). Even 35k has 8 days, SE as much as 14.
Most of the time you'll be wait listed, for anything close to popular routes. OTOH, plenty often I've seen J with empty seats, and I've even been opUp'd where they would happily have taken someones credits over me. YMMV. Good luck!