Carla,
This has been covered ad naseum of late, but since it seems to be a question, here is how people (me) do that without freezing:
First, just because they are leather doesn't mean they aren't for winter. Don't mistake a pair of Hi-Tec leather boots with a pair of Solomon (for example). My leather upper boots have a full plastic rand around the botton, making them fully step-in crampon compatible.
Second, my boots have fully leather-lined, making them the most form fitting and comfortable things on my feet.
Third, I have always worn the exact same things on my feet in them: Just a pair of VBL socks. Other than that...just bare feet. This ensures the best fit and comfort for how I fit my boots.
Fourth, since my feet are in VBLs, the inside stays 100% dry. Therefore, no freezing of the boots. When I'm hiking, my feet don't get cold since they are properly fitted, dry boots and I have room to move my toes.
When camping, I wear camp booties anyway so the boots come off. Again, since the inside is dry there is no problem putting them on in the mornings.
While plastic boots have come a long way in the past 10 years in terms of softness and comfort, they can't compare to a properly fitted fully leather boot.
Only posting in this 'plastic boot' thread to answer a question. Not interested in a debate between the two boots. To each their own.