In 2002 Michael Schumacher won the WDC with 6 races remaining.
Mind you that there were were only 17 races in total that season, so he took it just before two thirds of the season was done.
This season will have 22 races (excluding the cancelled ones), and two thirds of that is 14.7 races. Since the next race will be number 15, he will not be able to break that in terms of relative progress in the season. He also cannot beat the 6 races, because to do it with 7 races left he would have to become WDC in Singapore, which is mathematically not possible. He can (theoretically) do it in Japan, so he can still equal that record, albeit with more races in a season…
In 2002 there was still the old point system. Maybe that would change your calculation.
