What we need to remember is that the temperature is cold. Cold air is denser than hot air. Firstly, the ams will open less cooling inlets and outlets, because you don’t want to overcool the electronics, engines etc. that means you get less drag.
Next, you have to remember that the air going in the airbox (which mixes with fuel) is denser AND cooler – meaning the engine output goes higher.
Finally, the denser air also means more downforce.
Having these 3 plus points, cold temps can be a good win, as long as you can get your tyres to enough heat, the things should be rosy.
In another perspective – you have to ask why Mercedes and Ferrari could get good heat into the tyres in the cold temps that the tyres weren’t made for, and what would happen to those tyres in hot conditions.