The developer clarified that CDPR expects the game to reach up to 90% load on eight-core processors. To check the system's condition under load, he recommended using the program Cinebench or its equivalent.
The programmer added the game will not constantly load your CPU, but noted that insufficient cooling could still lead to performance issues or crashes.
As for specific processors, the i7-8700 and AMD Ryzen 7 5800H units should do the trick. The Phantom Liberty expansion will be released on September 26th.