Well, with the 720 Scania I was driving for a while, the boss told me that if you're within 2-300 Kim's from home (he had an IBC of Adblue in the shed) and the light comes on, just stick a garden hose in it to top it up enough to get you home. Never had any issues and he'd been doing it for over eight hundred thousand Kim's. He said he had seen the inside of an Adblue tank at the dealers, and it had about an inch of urea stuck to the sides.

