OTOH, if you are able to score some 20w50 on sale cheap, I wouldn't hesitate to run it. But most of the time it's easier to find 15w40 on sale. I would run either.
I grew up in Corvallis and worked in an auto & machine shop there when I was in high school and we used NAPA 20w50 in every domestic V8 that came in the shop in the 80s, including in the coldest days of winter. I think we used 10w30 in the imports, but there were a lot less of those.