RESOLVED: nvlddmkm.sys BSOD - Blue Screen of Death - I am writing in the hope it helps others!
2-3 times a day I encoutered BSOD (nvlddmkm.sys). I updated the driver from 372.70 to 375.70 as per https://www.techinferno.com/index.php?/forums/topic/10516-error-43-with-nvidia-37290-and-newer-drivers-use-37270/&do=findComment&comment=153291 (on ExpressCard) but it didn't help.
I noticed that the problem seems to occur when a big mains power device was switched on or off. I plugged my Dell 220W charger into my UPC, which also has a surge protector built-in. No BSOD's since then for 2 days (knock wood).
Setup: Lenovo W520 + Beast v8 EC + Dell 220W charger + GTX-1060 .