Another way to back up tabs for workspaces is the following:
In each workspace, right-click on a tab in the tab bar, goto "save", and choose "all tabs to a speed dial folder". Then, on the start page, edit the name of the folder and change it to the name of the workspace.
Then, goto the URL opera://bookmarks, and use the drop-down at the bottom left to export your bookmarks (which includes speed dials and folders on the start page) to an HTML file.
Then, if you ever have to, you can goto the URL opera://settings/importData, select "Bookmarks HTML file" in the drop-down, and import the HTML file.
Then, while in each workspace, goto the URL opera://bookmarks, find the imported speed dial folder for the workspace you're in, right-click it, and choose "open all in tabs". Or, if don't want to switch workspaces each time, you can right-click, goto "open all in workspace" and pick the workspace you want to open them in.
Of course if you lose the workspaces themselves, you'll have to recreate them before you can restore the tabs in them.
Also note that if you want to back up bookmarks without exporting, you can close Opera and back up the "Bookmarks" and "BookmarksExtras" files in the profile folder (after saving all your workspaces` tabs to speed dial folders). Then, if you ever needed to get things back, you can just replace the existing files with your backups and then use the "open all in" options as mentioned above.
The downside of saving opened tabs this way is that you have to manually delete the speed dial folder for a workspace and resave it each time the tabs in the workspace change. No one is suggesting you do that all the time, but it can be useful to back up tabs in this way once in a while just in case you lose everything.
