I am in Cherokee County, GA, and it gets plenty cold here. But I have allergies and when the chance to finally live without carpet came up I jumped right in.
My place is up 24", set on a cement block foundation/skirt, with vents and a crawl space hatch that is just waiting for spring and repairs to make sure it will finally completely close. In other words, it's a little exposed right now
The guy was surprised when I told him I didn't want carpet-he said it would get cold, and he was right.
Until I went along all of the baseboards with a nice bead of clear silicone caulk. I went along the entire interior perimeter of the house, caulking the area along the top of the baseboard where it meets the wall, and then I came back down on the area that meets the floor.
It is a lot warmer now even on the coldest days. I don't go barefoot very often at all, but have noticed a difference now the draughts are gone. Before it occurred to me to caulk the baseboard my feet were always cold.