Is there a way to manage a vocabulary with drag&drop when there are more than 100 terms? In Drupal 7, out of the box, it looks like the manage vocabulary page at  /admin/structure/taxonomy/myvocabulary handles 100 terms.  My vocabulary has about 500 terms, and I'd like to rearrange it into a parent and child structure.  Ideally, I'd like to get it all on one page to manage; is there a way to do this?

Otherwise, how am I supposed to reorganise a vocabulary spread out over 4-5 admin screens?
Have you looked at taxonomy manager?

https://www.drupal.org/project/taxonomy_manager