I haven't run into this yet..... even being from western New York...... but turkeys sure do love a hot lunch.   

And I suspect turkeys would cluck and purr while scratching and eating.  I think I would just set up and listen at first light.  If you hear them talk, I'd make a few soft tree calls. 
If you don't hear any gobbles, I'd make a few assembly calls.... and maybe even a fighting purr call. Make it sound like a small flock. Then just cluck and purr every now and then to make them think the flock was eating. 
I don't think I would even bother with decoys.... but you might put out a few.
Good luck and let us know how you make out.