I think Grand Finale in Sharonville {northern suburb of Cincinnati} does a Thanksgiving buffet ~
http://www.grandfinale.info/
Chez Nora in Covington KY, I think, does one as well ~
http://www.cheznora.com/about.htm
I'm not sure if these places still do them, but you can call or e-mail to inquire about it.
Cincinnati.com will have more info about Thanksgiving restaurant meals as it gets closer.