*Note the following works in Logic (and hopefully in DP so try on a test-file.)
Assuming you still have the Melodyne Editor active on the track, there is the option: "Move the distance". Editor can't know about your re-arranging unless you tell it, so if you move audio in your host you'll have to move the blobs accordingly to the same bar/beat position inside Editor. Select All, Copy, "Cut" & Paste at new position might do it since edits will follow. However if not, using select all and drag is also workable, just keep on dragging gently (even beyond the limit of the Editor file size) and drop the vocals where you want and continue to work at the new position. If you do not "set replace ranges to notes" the former blob-area will be quiet. If you have an odd start of the audio, copy/paste a blob to file-start as a reference before copying or dragging. It doesn't matter where the DP audio file is, Melodyne rules. Is this 'repositioning' what you want to do or did I misunderstand everything?
This repositioning can be well worth the effort (20 seconds) if you have done extensive editing and want to keep and continue edits on the new location while having the options to reset, alter and undo. Only make sure the DP song end covers the last note 'inside the plug-in' before bouncing since this point could be the new song end. I hope this works similar in DP, in that case you can-Dan