You can decide whether sold-out or expired products are displayed in your shop or not.
This setting can be changed in your Dashboard > Shop Configuration > Offer display settings
Place a check next to your desired setting, then click on the Save button.
Additionally, you will have to change the validity of your offer to Specific dates / appointments during step 4.Validity, to make sure expired or sold-out offers will still be shown in your Dashboard.
Furthermore, you have to set the dropdown menu in step 7. Preview to Calendar in order to make this work.