I know this is not exactly what you asked for, but I would still cheer for Sadguru Jaggī Vāsudeva here. He is 62 years old, and as far as I remember he has been working almost non-stop for the last (at least) 30 years, sleeping between 2.5 to 4.5 hours (and only lately close to 4.5 hours, most of the time lesser). I don’t know if he will stay past 80, but I guess he has already did many many ordinary lifetimes worth of work here in terms of the magnitude of the energy brought into this Earth. To be honest, I haven’t personally met with him and only know him from his videos and one of his online courses. Still, I feel you are probably searching for the proof of the power of life in an elder person who takes an active transformative role in society, and looking at his white hair and rich beard, perhaps you will see an elder person who is not ‘old’, but lives agelessly. He doesn’t even feel the need to live long from what I hear from his speeches, but people will most surely remember that he did live, because he has been truly living, is truly alive. And I think he can go any time he chooses and he will choose the best time for sure. An inspiration for sure! Cheers!