Like ronn said it varies.. In past experiece though they usually go down within 100 or less (easy). If your not confident after your shot just give the deer some time before you track it. That way you dont jump it up again to run some more. (prob into someones back yard) If I was hunting the center part of the 8 acres I would not be concerned that it would move to far into the subdivision part of the neighborhood.
Do you have alot of deer that uses those woods? I have heard of new neighborhoods having alot of problems of having their flower beds, gardens, etc torn up by deer. Hopefully you will receive no grief from neighbors in case your deer does end up in their yard. Just take it back in the woods before you field dress it.
Good luck with it. You never know those 8 acres could be housing a nice buck with a new subdivision around it.