The latest numbers I've seen say that around 26% of PC users are/will still be using Win 7 on Jan 31, 2020 (that's millions of PCs btw):
"...Computerworld's latest forecast — based on the 12-month average — has Windows 7 powering 26.2% of all Windows PCs on January 31, 2020, nearly two points lower than the prediction of only a month ago and 4.5 points under July's prognostication. But even a year after its departure from public support, Windows 7 will still run an astounding number of personal computers.
In January 2021, Windows 7 should still account for 12% of all Windows operating systems, about one in every eight PCs and equivalent to approximately 180 million machines...."
