I think you have to throw the $20 mil thought out the window because it just is what it is and you can do nothing about it. The real question is how much can pay Brees and then add $20 mil cap on top of that. Does Brees agree to $25 mil salary and the team take a $45 mil cap hit this year OR do they kick $20 mil dead money to next year.
I disagree with the OP that the saints would in any danger of competing for a top pick in 2021 draft. If the defense stays the same the Payton will have the offense running with whoever is at QB and they will still be a playoff contender.