Be prepared to find limited services in the winter, the off-tourist season. Hotel rooms are still available, but the main restaurant in town is shut down at the time and everything is pretty quiet. However, the souvenir vendors are still ready for business! The ruins themselves are also open and easy to visit with little stress. When we went in February, we were almost, but not quite, the only people visiting the sites at the time.
I’ve seen this amusing warning sign in Yazilikaya. It must have been meant: don’t climb up the rocks or 1000 gods of Hattusas will throw you down, haha!