If it's any help I spent the first week in January in
Icmeler and
Marmaris (there for New Year) a couple of years ago. Icmeler centre was like a ghost town and it's really bizarre to see it like that when you're used to it so busy in the summer months, though there were a few places open in the village.
Marmaris was busy with plenty open as many people live there all year round and although I don't really like Marmaris in the high season I have to say it's a very nice place to be in the winter.
I remember we had a couple days of rain (the sort of rain you really couldn't go out in) but the rest of the time it was sunny and warm - well like it is here when we get a nice warm spring, certainly a lightweight jacket was adequte, I remember we even ate breakfast outside on Mamaris Marina one morning in the sunshine.
Think there are more places that stay open during the winter now in Icmeler as more and more people have bought homes out there and of course there are more direct flights to
Dalaman from the UK - certainly Ozzy's is open and he was saying he gets quite busy, they do quiz nights, karaoke nights, bingo that sort of thing.
You should go for it!
Mazz