In the canonical play Harry Potter and the Cursed Child, we learn that, in 2020 (Albus Potter's fourth year), the trolley witch on the Hogwarts Express has been working in the train for 190 years - she says she was hired as protector of the train (and tasked with preventing students from jumping off it) by Ottaline Gambol, Minister for Magic from 1827 to 1835... If the revelation of her age is played for laughs in the play, it still calls into question the very reason why Voldemort felt compelled to create Horcruxes!
Furthermore, the play shows that McGonagall (born in 1935, 85 at that point) is still Headmistress of Hogwarts, that Madam Pomfrey (who already worked there in 1971, leading a young Lupin to the Whomping Willow) is still the nurse and that Madam Hooch is still the Flying instructor. Although, for instance, Professor Sprout (who, dixit Pottermore, studied at Hogwarts roughly at the same time as McGonagall) has been replaced by Neville in Herbology and there is a Professor Mazoni either for DADA or Charms (in which case he has replaced Flitwick, who was already supervising the Marauders' OWLs in 1976).
As you mentioned, JK's old site's Wizard of the Month feature, Dumbledore was revealed to have been born in 1881 - and we know he was killed in 1997, so at 115-116 years old, at which age he still was able to swim to the grotto containing Voldemort's Locket Horcrux.
On Pottermore, JK writes that Isolt Sayre, the founder of the American Ilvermorny School of Witchcraft and Wizardry, died at 100 years old - in other words, the same age as her Muggle husband... Has magic helped keep him alive that long? Also, by 2020 Petunia Dursley, born before 1960, has died, at a relatively young age for a Muggle woman.
But one could put a caveat here: if wizards like the trolley witch and Dumbledore can live longer than Muggles, it seems they are quite often prone to magical illnesses that can make them die prematurely - like dragon pox, whose victims include: Minister for Magic Eldritch Diggory (at an unknown age), Abraxas Malfoy (whose son Lucius was born in 1954, and who died before 1996), James Potter's "elderly" parents Euphemia and Fleamont (who had him late in life), and the apparently middle-aged parents of Tina and Queenie Goldstein.
Another magical cause of death was also brought up in Cursed Child: Astoria Greengrass (Draco Malfoy's wife) died at 37-38 years old of a "blood malediction" cast on an ancestor of hers.
Of course, if you take into account the two wizarding wars, average wizarding lives become even shorter - Colin Creevey died at 16 years old, Fred Weasley at 20, Lily Evans and James Potter at 21, Tonks at 24-25, and Sirius Black, Remus Lupin and Severus Snape all in their thirties.