I had the same problem in Tx last week.
We normally have wheat that's 6-8" during the opening week but this year, it was going to be up to a good gobbler's beard or higher.
I ended up killing one that came from a wheat field but he walked the edge on where it was shorter and right down to me. They seemed to use the edges where it was shorter, just like they would a logging road and would much prefer to stay on the out skirts of the wheat. Having said that, I saw gobbler tracks going right in to the center of one of the big fields so I guess they will still walk in it.
At the end of the week though, (it was a 5 day trip to TX) we killed more in the mesquite around the wheat fields than actually on the fields and it's usually just the opposite in years where the wheat is shorter.
A couple years ago I killed one that you could only see his head and he crossed about 300 yards of it to get to me so they will do it but I think they like it a lot better when it's shorter.