When Mahoney turns 80 and is no longer eligible to sit on the College of Cardinals to elect a pope.
Here in Chicago we’ve seen it every time; when someone becomes Abp. of the Diocese of Chicago they get a biretta at the next Conclave. Our current Abp’s prececessor died, so I don’t remember if there was a “wait for your predecessor to age out” issue.
Well, that’s assuming he lives to 80. But no, we’re not supposed to hope that he won’t. . . . We’re supposed to pray for his conversion before he dies.
In any case, it will be a year or two or three at least, since a consistory was just held last fall.