Well, I seem to recall that "the best layed plans of mice and men often go awry", or something to that effect. IF the birds are roosted in exactly the same location opening day, which is still several days away, then I'd slip into the timber well before daylight between the hens and gobblers and try to kill one before the birds ever go to the field. I've gambled on setting up on a field near a roost area many times through the years. Sometimes it works, sometimes it doesn't. Occasionally, like this year in Alabama, when my buddy and I got a double, the birds head straight for the field and the plan works. However, a good percentage of the time, the birds end up staying in the timber and never make it to the field. That happened to me last year here in MO on a field in which I had killed birds the two previous years. For my money, a safer bet would be to try and intercept the birds in the timber, especially considering the other hunter. Good luck.