For anyone using RX 6000 (RX 6800 in my case) cards on Windows 10 experiencing driver, miner, or OS instability:

Lowering mining intensity (-mi) to a lower value, where you just start to lose hashrate, can bring your stability to ~100%

In my case -mi 4 completely ceased driver timeouts and crashes...for the price of .3 MH/s when no other applications are open.  My system remains stable no matter what other loads I place on the GPU.

My average hashrate is up...since I never have timeouts or crashes now!