Thanks for the guidance on collecting the debug info needed.
So I uninstalled the video card (via Device Manager) while in Safe Mode, checking the box for uninstalling the drivers too. I rebooted into normal Windows and downloaded the latest Nvidia driver package for my GPU. I then went back into safe mode and installed the driver package; MS had not been able to auto-install my GPU yet.
When I rebooted I checked the Device Manager's hidden devices and found a bunch in audio drivers (maybe DDU isn't great with the audio drivers associated with a GPU?). I am using both a DVI and HDMI outs from the GPU. I then tried sound via using iTunes and the computer crashed almost immediately when sound started... so I rebooted and uninstalled all the hidden devices under audio devices in Device Manager. I am currently stable but need to test it for a few days because the system crashes are not predictable.
If still unstable I will try the clean uninstall via DDU in Safe Mode, and install the new GPU driver package in safe mode as well (so MS can't even try).