Woodpecker templates are just regular Word documents (with super powers). Each Woodpecker template is just a ".docx" file that can be treated the same way you handle any other Word document.
When you create Woodpecker fields and insert them into your document, the field data is stored as metadata within the document itself. Whenever you open up Woodpecker, the application reads this metadata and displays the field data that has been created for the document.
If you discontinue using Woodpecker, the templates you've created will function as normal Word documents. You will of course lose the ability to automatically populate the template using Woodpecker, but your document will otherwise remain intact.