Nowhere on the above the map or in the text of CSWE is how big each hex is and has remained a minor mystery for the past 35 years.
Recently I realized that the city map to Tarantis is drawn in a similar style to CSWE. While it doesn't have hexes it does have a scale.
So I superimposed a section of Tarantis on top of CSWE and resized Tarantis until the main street, alleys, and building look comparable to the same on the CSWE map.
I then made the Tarantis map transparent and moved the scale over on of Viridstan's hexes. And viola! It looks like each hex is 120 feet.
While my works is an elaborate guess it makes a lot of sense. It unlikely to be 240' feet, but it could have been 60 feet. Or the 60 yards of the Thunderhold Map. Making the scale 120' would make the size of the building comparable to those in Tarantis.
If I ever get around to drawing the City State of the World Emperor that the scale I will go with.