If you have Witcher 3 from GOG you can choose the version you want to play with. You can also download the specific version and install it anytime you want. (off line) No DRM. Even if they update it, if you have it there you have no problems.
If not, it will suck a bit IMO. Wait until it is on a great sale and get it on GOG. You can keep the new one as they fix the issues, if it ican be fixed, looking at you Cyberpunk 2077. It was total trash when it was released and now is considered a decent game.