You may use sync using your Opera Forum User/Password and save also open tabs as well as your custom data.
This is what Opera Sync syncs:
But make a Folder Back Up it's a full bckp, so Sync.Opera.com do not bckp some stuff like extensions and it's config, other stuff don't remember since I use Sync but make Folder Bckps, also easy to manage multiple profiles.
To find the path:
OMenu > About Opera > Paths >> Profile