Isadora 3 will automatically deactivate and revert to Demonstration Mode when your subscription period ends (such as if you cancel your subscription). 

If you later renew your subscription, rent Isadora again, or purchase a buy-to-own, simply repeat the activation procedure again.

Any saved Isadora 3 files are not affected in any way. These show files may still be open and run while Isadora 3 is in Demonstration Mode, but you will not be able to save any changes, nor you will be able to save any newly-created projects.