Finally got my first CEL/Glowplug/limp mode

Or not technically the FIRST - once, a couple months ago, the car ('15 GSW 6MT) randomly lost power & glow plug light came on. Pulled over, shut it off, restarted, no sign of trouble after.

Yesterday I headed off to work and got 5 minutes down the highway in MILDLY cold weather (35f) when I felt a stumble, then felt nothing in my accelerator & saw the glow plug flashing. Pulled over, pressed the start/stop to shut off, but the car sounded like it was trying to restart. Pressed agin, car shut off. One more attempt to pull onto the highway, immediate limp mode again. So I waited a few minutes, restarted, got to the office without issue and made an appointment at the local volks dealer becuase I still have some time on the dieselgate extended warranty.

This morning, same temp, same thing but now with a CEL on (just the glowplg light alone yesterday). Went out for lunch and it's fine, no more CEL. I'm guessing my ride home will be fine too, so far it's just the cold?

This does not seem to be an UN common occurrence on these cars, and I'm headed to the garage wednesday, but who else has dealt with this? Are there simpler solutions I can try/look into ahead of time?