This product was more common in the Canadian market many years ago. Most of us here should know that oil companies try to use gimmicks or target markets for synthetic blends, because otherwise, people buy conventional or they buy synthetic. This blend was common before HM synthetic blends became the next big thing. In the interim, this version of QSED was replaced by the HM QSED, and then Defy. I haven't seen this winter QSED on shelves for a number of years. HM synthetic blends and dexos1 synthetic blends are the current marketing strategy.
And yes, a 5w-XX is a winter oil (I call it an all season oil). It's -30 C out right now, and was -35 C yesterday morning. I call that winter, and I almost always run a 5w-XX, including today and yesterday.