My 17th generation is aging up to a child today for my drifter challenge, I've been playing this save since October 2018.
The drifter challenge is a legacy challenge, of sorts, as it spans across multiple generations if you do the whole challenge and not just the individual house challenges. By the time I'm through the whole challenge, I'll be on Generation 24. I doubt I'll give up my Schmitt's after that, though. I'll likely continue with them and see how far I can go. They are the sims I am most attached to.