I have always gone to SW Kansas the first weekend of December figuring that most hunters will be out deer hunting. It has always been a really great plan until the last two or three years.
Lots more bird hunters out the last two years especially. Used to be that we could hit WIHA all day and maybe see one or two other groups. Last year we saw one or two groups on our way out of the first field. The last few years we try to be extra-thorough in the first field, knowing that it's the best chance we're going to get all day. After that, you should expect to be the second, third, fourth, etc, group to hit each field. Better shoot straight, you may not get a lot of chances after sunrise!
FWIW, I really like the Dodge City/Larned/Greensburg area. I'll keep going back as long as I can find a few birds here and there.
P.S. I also personally like that area because I have family down that way and because for some reason I shoot really well out there. Hope I'm not jinxing myself, but I haven't missed a bird in 2 years! (In that area) I miss birds all the time other places...