Video -- Free Up iPad Storage

See Apple article here for deleting items from your Apple Photo library.

Also, in Takedown>>Schedule>>Event>>Manage Video, swipe right to left on any match for which the associated video is on your iPad (indicate by black filmstrip icon at far left). Tap "Delete." Caution: don't do this prior to uploading to YouTube.

Side note: if you want to preserve the original videos, then after uploading them to YouTube you can copy the original videos from your iPad(s) to a compatible device or cloud service.

Lastly, you can also free up storage on your iPad by deleting unused apps and their associated data.  See Apple article for more information.