CD Projekt Red has revealed that it's actually remaking the first The Witcher game, and it'll be built "from the ground up" in Unreal Engine 5. This is the true identity of the company's previously announced 'Canis Majoris' project.
CDPR stresses that the suitably titled The Witcher Remake is still early in development, and the game's being spearheaded by fellow Polish studio Fool's Theory. It'll probably be a while until we see anything of it, then, but it's potentially exciting news for fans of the series.
Fool's Theory, by the way, specialises in RPGs — and some of its senior employees worked on The Witcher 2 and The Witcher 3. As such, the project should be in good hands.