Like, for a trenchcoat or duster, you could have the option to button it or leave it open. Buttoning it would increase coverage and warmth. For hoods, give the ability to push them back. It would, of course, lower warmth, and the coverage would drop to near-nothing, but it’d give a way to cool off without having to remove the hood entirely (adding to the volume of one’s inventory).
You could fold existing hoods into this system too. Use a raincoat, be presented with the option to raise the hood or lower it (or button the coat!).