You can follow my instructions on this here:
-Diablo IV has run out of memory - #103 by DTMAce-1687
Instructions on dealing with nVidia driver changes:
-Game crashing after Nvidia Update - #2 by DTMAce-1687
Keep in mind, the specific driver version I mentioned is only for the 4080 Super (as it was released on Jan 31st)… But you can use a driver from just before or just after.