The calculated distance (air line) between Groß-Enzersdorf and Mödling is approximately 15 miles respectively 23 kilometers.
By car or train, the actual journey to Mödling is certainly longer, as only the direct route (as the crow flies) between Groß-Enzersdorf and Mödling has been calculated here.
Air line (approximately)
23 kilometers
13 nautical miles