Answered question
according to this https://fizz.ca/en/faq/what-is-rollover-and-how-does-it-work the rollover is 1 month, I am pretty sure I saw 2 months when I signed up, did that change?
Well that's what it says on the link you provided
"Each batch of rolled-over data will expire after 2 complete payment cycles (your current payment cycle plus two more full cycles)."
Cheers :)
Other answers
Its 2 months