Is 'offline' defined as in a localhost Moodle used for development?
If so, one could backup courses on the localhost Moodle then restore to the online Moodle server ... assuming the 'offline' Moodle is the same version (or at least NOT less than) the online Moodle server ... and that your backup is not larger than the online Moodle server will allow for uploads. If your localhost backups are larger than the size allowed to upload on the online Moodle server, one could setup a 'Restore' course with a file system repo. The file system repo is accessible via FTP/SCP which wouldn't be under the PHP/Moodle restrictions as to size. All course restores are done from the Restore course to other Categories/Courses.
If I'm not understanding, please provide some more details.
'spirit of sharing', Ken