First off, and we would all agree, any time is the best time to kill a big buck. However, IMO there are 2 easier times to do it. First is like you mentioned. Right in the begining of the season and for the reasons you mentioned. The second is during the rut. This is when the big boys slip out of their nocturnal patterns from earlier hunting pressure in pursuit of breedable does. During this stage it pays to be in your stand all day. You never know when that big boy will be chasing right past you.
It is also pretty common to shoot a buck the first time a stand is hunted provided the wind is right and you get in undetected.