My mom used to drive a 68 High Country Special Mustang when I was a kid. We sold it one winter because we thought the engine froze up and cracked the block. Come to find out we were getting fuel from a station that had water in the tanks. It froze that engine up tight. We ended up selling the car for $600 then 6 months later we saw it in a Mustang hot rod magazine talking about how these cars were special built in Devner for the Colorado mountains and they only made 6 of them.
I have seen fuel pumps freeze up in winter, and I always get gas at the name brand places.