As expected, the "XXX miles to no start" message has started appearing again now that it is winter. This happened repeatedly last winter, which was the first since buying our 2013 Passat TDI SEL in July of 2020. It was taken to the dealership in Milwaukee twice, but no fix.
Our daughter has been driving the wheels off it, putting 33,000 miles on it in a year and a half. It went all summer without giving the AdBlue warning, but that changed once the weather started turning colder. As someone else reported, short trips in cold weather do not trigger the warning, just long trips. Also, as others have reported, the warning generally starts at 200 miles (not at the 1,200 or 1,500 miles it is supposed to) (or less), and the trip from Eureka to Milwaukee is longer than that -- and, yes, it will brick the car if it goes to zero. (We've experienced that twice.) In all instances, there was plenty of AdBlue in the tank.
It threw a legitimate AdBlue warning at the designed starting mileage before the weather turned cold, and the level was indeed low, so it appears that the injection system has been working and using AdBlue. But all of the other times, it has thrown codes P204F, "Reductant System Performance Bank 1," and P20EE, "SCR Nox Catalyst Efficiency Below Threshold Bank 1."
Based on a YouTube video showing the cleaning of a caked-up injector and port, I pulled the DEF injector on ours only to find both injector and port very clean.
I'm about to call Volkswagen Customer Care to see if they have a fix for this yet. I can't have our daughter risking being stranded alone at a rest stop or fuel station with a car that won't start at night in the middle of the winter, so I sent my BlueDriver with her so that she can at least clear the codes. Any updates on this from the group will be appreciated. Thank you.