I just saved one sim from Grim after she collapsed from freezing. She was on the street in front of my sim's house and my sim convinced her to group up. It would take too long to walk back to my sim...
How about game opting out the "go jogging" in Winter? Most of my sims wouldn't really mind, besides we would avoid seeing blue npc's jogging around the hood. My only sim who might miss winter jogging, can go visit the gym instead. Where I live most people do that in Winter, and when Spring arrives the streets are full of joggers again :)