Everyone has different criteria when it comes to judging resort size. Some might look at acreage, others vertical drop, or maybe even cumulative run length.
Guttentag, Christoph Schrahe. This German ski consultant independently measured every major resort (using maps and satellite data), and created his own infographics to convey the data as published Financial Times. Which measurement do you think is most important? 
[images from financial times & pistenlaengen.com]