it'd have more to do with sunlight and ground temperatures ..... the ground temperatures are more stable than the air temps ..... the turtles that successfully hibernate are the ones who find safe stable areas to hibernate in ...... under leaf cover , composting organic matter , rotting tree stumps , anything that insulates the ground will stabilize the ground temps ......... i believe usually south facing sunny spots , that don't flood .....
I’ve spent time up in the panhandle during the winter and I’ve seen a few adult box turtles out and about in December. But these were on relatively warm sunny days, or during the rainy periods just before a cold front arrived.
Like most turtles up there I think that some ADULT box turtles do become active during warm spells.