No, changing templates is not possible, but you can use the following workaround to copy your presentation’s contents to a new presentation with a different template. To do so:
Select All (CTRL/CMD+A) in your presentation and either
- copy and paste the contents into the new presentation.
- add the selected content to Favorites by right-clicking and selecting Favorites.Then in the new presentation, insert the content by going to “Insert” and clicking Favorite. If you cannot see your contents in the Favorites sidebar, please refresh the page.