When I take mine off the plastic is usually cold because I use them in the snow. Where sir do you ski? Or did I miss you say that you wear them on the ride home?
The liner is warm, but that means nothing, its an intuition liner and is firmly molded to the shape of my smelly foot.
i dont really do either, i keep them buckled the exact way or at least as close as possible to how i wear them when i ski. its better that way because they will be in the shape you actually use them, rather than being bigger or smaller
i definitely buckle them religiously, i think its pretty standard
tight as a nun.