Isn't this what road signs are for?
You’re absolutely right. You just do what you need to do.
Having some form of inertial navigation supplemented by GPS and visual odometery from features that stick out from the side of the road (like a road sign; memorized by the vehicle on past drives) would help a lot. A HUD UI could show road markings on “slice” of the road.
Call it “low viz aid” or something catchy.
In my case, I was driving on a rural road just before dusk without street lighting where there is nearly no traffic on a good day. Low-beam headlights were reflecting off the flakes and high-beams were obviously out of the question.
Risk of a collision with another vehicle was low, but going into the ditch was possible if you didn’t know the bends of the road.
Yes, these are dangerous conditions, but I started off driving in rain and didn’t anticipate the switch to snow mid-drive.
But yeah if you can't see the road markings due to an active blizzard, flip the hazards on, follow the tail lights ahead of ya, and stay in the middle of were the road should be.