Let me try and shed some light on this subject. I'm by no means an expert, but I think I have a pretty good idea about how all of this works.
When a doe goes into estrus, that is the time she is actually allowing a buck to physically breed with her, she will only be in estrus for about 24-48 hours. In that time, she will often let multiple bucks breed her.
During the peak of the rut, an increase in testosterone in bucks will cause an increase in the size of his testes. In the couple of months coinciding with and following the peak rut, a buck will breed with as many does as possible. Bucks often run themselves ragged following does and fighting other bucks for dominance and many bucks lose a considerably amount of their body weight through the month surrounding the rut, and sometimes can't get their fat reserves up before the winter and die due to malnutrition.
If a doe isn't bred during her first estrus cycle, which is uncommon but not unheard of, she will go into estrus about 28 days later. This often leads to what many people consider the "second rut." A month following the first real peak of the rut many yearling does will also come into estrus for the first time. Does not bred during this estrus cycle will have another estrus cycle 28 days later. Once a doe is successfully bred, she'll stop creating the estrus scents that put the bucks in her area into a breeding frenzy. In areas with a buck:doe ratio that is out of whack (too many does, not enough bucks) does sometimes go into 2, 3, or 4 estrus cycles before being bred, leading to late-born fawns.
Now on to nratc's initial question. If there are as few does in your area as you say, the bucks that call that area their home range may move off in search of other does, but they might stick around and try to rebuild their fat reserves, depending on how much competition there was to breed those does. That being said, even if you assume all the does have been bred, bucks from nearby may come through your area in search of receptive does. A buck has to scent check an area to know if there are receptive does in the area, and he has to visit that area to do it.
The bottom line is don't get discouraged because you think all the does in the area have been bred. This could be a good thing. It may make the use of estrus scents more effective, and if competition for the does is high, rattling might also be another successful tactic.
Hopefully this answers a few of the questions.