No, feral do not hibernate in winter. No cat, wild, feral, community or semi-domestic hibernates. The cat is one of those species who do not hibernate.
Although it might seem strange to some people, web surfers do ask Google the question in the title, which is why I am responding to it.

Hibernation is a state where the animal’s metabolism slows down and the body temperature drops allowing the animal to see out winter without having to find food which is potentially scarcer. Animal that hibernate do so to varying amounts depending on the species. Before hibernating, animals put on weight to see them through the period of inactivity.
I can’t find information on why cats don’t hibernate while some animals do. I’ll have to apply common sense.
The feral cat is able to find food at anytime during the year. Therefore there is no need to hibernate. Hibernation is designed to allow animals to survive lean periods when prey or foods are scarce.
Evolution is important here I’d suggest. The ancestor of the feral cat is the North African wildcat. In north Africa the seasons allow hunting at all times. There is no need to hibernate. The evolution of the wildcat has been carried forward to today’s feral cat.
Some cat owners might think their domestic cat is hibernating if she snoozes a lot during the winter months when she likes to stay indoors!
Comical. No, not one cat in this world hibernates, ferals included. But, because of the weather, I draw them out to feed differently than in warm weather.
Thanks Susan for chipping in.
Of all the feral cats I’ve rescued, or fed and watched over, None have ever hibernated. Their daily habits may have altered a little, but none have ever hibernated. And the 4 Who are with me now, are napping more, especially at night.