You could try some 0w40, man that stuff lets the engine spin fast at negative temps!
Never had a problem with cranking speed with any Modil 1 weight. My cars always spool up instantly on those 0 degree days. Had 15w40 Delo in the SD last winter. It was fine until it got below 20, below that you really noticed the drag.
This winter I might try some 0w40 in the SD to see what I gain.