The Witcher remake was announced earlier today! Confirmed by the studio themselves.
The game will be built from the ground up using Unreal Engine 5, and it's currently in it's early stages of development at Polish studio, Fool's Theory. This studio also has veteran Witcher series staff involed, while CD Projket Red will be providing full creative supervision.
You can read the full statement from CD Projket Red here
There's not much else to be said at this point in time other than it'll be quite some time until the full game is released.