Windows 10 20H2 is still in single-digits.
Windows 10 OS Worldwide (PCs)
October 2020 Update is on close to 9% of Windows 10 PCs right now.
Close to 100,000 Windows 10 PCs were surveyed.
Windows 10 OS Worldwide History (PCs)
Windows 10 20H2 rollout speed seems to be on par with the previous few releases.
Note: we don't have the data for the initial rollout of the first update to Windows 10 (1511, also known as Threshold 2). So it's a straight line from 0 to the first data point we have on August 22nd, 2016.
Source: AdDuplex Windows Device Statistics reports