Are you aware that you can combine multiple network licenses into one license? If you have a mix of network licensed products, you can combine them into a single license file for running a mix of licensed products or releases.
This could also be the products you upgraded in Autodesk Subscription program. Then when you roll out the new version you could continue to use the prior release until all your users have migrated or moved to a new project to start the new release.
Knowledge Base Article from http://support.autodesk.com
Link to Knowlege Base Article
http://support.autodesk.com/getDoc.asp?id=TS65928
Cheers,
-Shaan
