Where I hunt mulies, you can walk as far as you want but there is no real need to leave the Jeep. The deer in farm country have no fear what so ever of pick-ups and tractors and such. In the winter you can drive right up to them with a tractor and loader. They see vehicals every day and in the evening I can park about 150 yards from where they come up from the breaks to feed and just wait. Its easy hunting for an old guy.
Last fall the biggest Mulie buck that I have ever seen (about 33-34 inch spead) walked about 100 yards from my jeep and never even looked my way. He is still out there because all I had was doe tags.