I talked it over with Ali and it seems like Arizona is my best bet for a December poker trip. Ali had concerns, not totally unfounded, that driving around Oklahoma during the winter could lead to weather I wouldn't want to be driving in. New Mexico got dropped because there are only 7 rooms in close proximity, so it could be combined with a sightseeing trip with Ali. Florida is kind of a waste of a trip because of the quality of the poker rooms and Southern Indiana suffers from worse weather than Oklahoma.
I've put together an initial road itinerary:
View Poker - California in a larger map
Approx. 1134 miles, without counting the casinos in Phoenix. Should be fun.