I prefer to look at how many starting years players have in the NFL as opposed to their actual age. It seems like the QB's that have had a long run tend to fall off around year 17. Peyton Manning fell off a cliff halfway through his 17th season, Favre had ups and downs along the way but hit the wall year 18, Brady is entering his 17th season (will he buck the trend?).
Brees is entering his 16th season and doesn't have a guaranteed contract for next season. At least Im pretty sure theres an opt out after this season. IF you're going all in for a win this year, I say make it happen. Otherwise, find a streaming duo and ride them this season.