Water would stop circulating which means it will not make it to the radiator to get cooled which= overheat. Water circulates through internal pockets/canals/pathways in the engine block/head to absorb heat and gets pumped/circulated to the radiator to cool.

 

i doubt your coolant will freeze lol. even if it does, you might get a little overheating but as soon as the icing melts from the heat the engine produces, you'll be fine again. there's no such thing as a 50/70 mix lol. you mean 30/70 right? just let some of the coolant out and put in more straight G12 if you have any left. if not, i really think you should be fine since you're only in NY. now if you lived in Alaska, i wouldn't be saying that haha

 

Every Audi tech I know (I know a few) uses a 50/50 mix regardless of what the bottle says. If you ran straight water then you'd have something to worry about. Even a very very weak antifreeze mix would keep the water from freezing. The main reason you need a stronger than necessary mix is to keep the radiator from corroding. G12 is great stuff. When is the last time you heard someone had to replace their radiator?

 

50/50 freezes at -40 F. 100% antifreeze at +8 F.
The universal yellow antifreeze allows me to add
if necessary at any gas station.