I'd say between 55-60. The battle at VoTE was when they were in their primes, which is roughly 23-28 given the respective prime for humans physically. If they were to be alive now, they would be between 110-113 (again, roughly). Give or take before the start of the series, Obito was 13, so he's 30 now. 14 when he attacked Konoha. Take off 16 years from 110 is 94 (What Madara would roughly be when he met Minato). 94-60=34. So give or take like 6 years, but in the 55-65 year range.