Just a couple of things to add as a basso. Yes it's true that age will extend a male's vocal range, particularly into the bass range, but I'd put my money on practice and confidence any day.
The lowest notes I've personally seen in a SATB score is the D just below the bottom line of the Bass staff, but that's pretty rare. I have a peronal ambition to get down to Bb but I'm still a tone away.
Don't forget that women's voices improve with age and get a warmth and sexiness that younger kids cannot achieve.