I like Jeff's range...but there are always exceptions.
The Adobe Course at the Arizona Biltmore (6,500 yards) sits on 90 acres. It is a core routing (Wm. Parc Bell), with many parallel fairways — the more efficient from a geometric perspective.
Jack Snyder created 18 holes, par-56 on 49 acres of land — Mountain Shadows also has a short range! — And, if that is not enough, it winds through a resort and housing. We are renovating and updating it:
http://www.golfgroupltd.com/mountain_shadows.htmlAnd, currently we are adding nine holes to an old course. The new land is only 40 acres. Par for the added nine will be 34...and we are currently at 2,600 yards.
These, of course, are exceptions. More land usually produces a better experience...but sites such as Merion are quite constrainted and yet enable a wonderful setting
and experience.