We had to make an emergency trip to Quebec in January 2022 because of health issues with the in-laws. Father-in-law advised to get the stuff rated to -20°F, but it wasn’t available where we live and I’d gotten the car serviced before we hit the road and they filled the washer fluid with what they had, I’m guessing 0°F. I bought some -20°F in Buffalo but didn’t have room to add any. The temperature was rapidly dropping as we headed farther north and as we neared Watertown, NY the fluid wasn’t spraying well. I tried adding what I could of the -20°F but by the time we stopped east of Montreal that night it was -45°F and the whole system had frozen solid. Tried using a hairdryer at the hotel, but we couldn’t melt it until we got it in the in-laws garage. Without fluid running the wipers can mean just smearing crud across your windshield, making it impossible to see.

Now I always make sure whenever we leave Quebec that I have a bottle of -49°F rated fluid and fill the reservoir at home before heading up in the winter. If there’s a lot of warmer-rated fluid in the car I’ll actually siphon it out.