My thoughts are usually within 1 1/2 miles. big bucks often have 2 or 3 bedding and feeding areas. He wont leave too far in new country that he doesn't have feeding, bedding, or water source.
One thing to remember, sheep usually graze in the same general areas, about the same time of the year. The buck is used to moving, I agree because of noise and smell. Would you like to live by a herd of Sheep? I have seen a 2 point buck water in the middle of 50 sheep at a water hole, which he didn't seem to mind. I don't know if he spent a lot of time in the same area.
Sometimes after a buck rubs, he will move to a new area also. More often he will still be in the same area. Good luck finding your buck.