You don't need to individually relink your interview templates to your base template. You can do this in bulk by taking the following steps.
Select the templates you want to link to the Base Template > then click "Base Template"
On the right hand side, you'll see Assign Base Template pop up. Select the Base Template you want to apply from the dropdown.
Select which parts of the Base Template - Event Titles, Event Descriptions, Candidate Event Details - you want to link and apply > then click "Link Templates"