Accoring to the user reports on https://www.protondb.com/app/292030 it seems to run very well.

Fun fact: the Kronos group added an optional Vulkan extension to simplify the implementation DX11 transform feedback.

This was requested by the DXVK developers specifically because it's was the last piece required to completely support Witcher 3.

Mesa and Nvidia had drivers support on the day (or shortly after) the extension was published.

FWIW my nvidia laptop also became a heater running Ubuntu (which Pop!_OS is based on) but has been running like a cool dream since I installed Manjaro (Xfce, out-of-the-box non-free driver setup).