Too close for me to call.
Age is having more of an effect on me in the heat. I never really got acclimated to riding above 95F this summer, so I'm limited as to how hard I can push without overheating.
But in the cold (which I generally define as being below 15-25F), I haven't found any clothing combination that will let me ride hard. Tights that keep my legs warm also constrict and drag my legs; a jacket which allows for inner layers also produces drag. And even breathing through a balaclava doesn't warm the air enough to keep my lungs happy. So there is some limit to airspeed when it's cold where I try to balance energy production from pedaling, and still stay cool enough that I don't sweat more than my clothes can shed. And that limit is slower that I'd ride if it were 70F.