After many hours of failed attempts to get Witcher 3 to run stably after leaving the "tutorial" area, I came across something that worked for me. I followed the instructions without deleting any dlls: Now I have it running and it looks better:

https://levelskip.com/rpgs/How-to-fix-crashes-in-The-Witcher-3-and-improve-performance

windows 10
AMD 1700x
GTX 1080