tl;dr: de-tuning the card seems to have helped for me. I don’t know if this would help anyone else, but I would be curious.
Longer version: a few weeks ago the game gave up for me completely, crashing to desktop with the 0x80000003 error immediately after starting (during the logo video or at the start screen at the latest), constantly and reliably. I had the issue before, but this time it was completely out of the blue: I had an about 1-2 hour session, a crash, and from then on the constant instant crashes. Also, this was after weeks without any game, driver or even Windows updates.
The card I’m using is a 1080 Ti, with factory (Inno3D) overclocking, and I haven’t bothered with the tuning utility with this card until now. The card’s clock speeds are theoretically 1607 MHz base / 1721 MHz boost for GPU, 11408 MHz for memory. The nvidia specs are 1480 / 1582 & 11000, so I tried to match these.
Tried different speed offsets (-278* / -408 and -140) and also adjusting just the GPU or memory clocks separately. Lowering the memory clock speed alone still caused immediate CTD, whereas de-tuning only the GPU seems to work. I still haven’t tried to find the exact amount of clock offset, currently -140 MHz (based primarily on the boost clock values) seems to be fine, without a too big performance impact (in places I could even swear it runs even better).
Slight caveat: after a longer session I still can get a crash with error code 0xc0000005, but that seems to be a RAM issue (and other programs also get that error, so that leaves me worried over other things).
*at first that was meant to be -139 MHz (= 1721 - 1582), but clicking “OK” doubles the amount for some reason, so to be careful I just left it like that.