Q: Exporting project when storage is full

I ended up shooting and editing an iMovie project and running out of storage space for new video clips in the photo app library. (Using a two-year old iPad v9.2 (13C75) iOS 9.2.1 iMovie v2.2.1)

I only had 2 gbs left of storage so I tried to save the finished video to the photo library as part one of my video. After that I would throw out the raw video clips in part one and start shooting and editing for part two.

But when I went to save the finished video to the Photo Library it said I did not have enough storage space at 1080p. It wouldn't even try an export. I checked storage. It read I now had 1.6 gbs. Down from the 2 gbs.

So I tried at 720p. Exporting started but before it finished it said I ran out of space.

I looked at storage. Now I had zero!

Why did that happen? Nothing got saved as finished video. Not even a minute of the iMovie project. The only thing in the library of clips is the original raw video clips.

So, using Airdrop on both the iPad and a Macbook (mid-2012 running El Capitian) I tried to transfer the iPad’s iMovie project, and supporting raw video clips to continue the edit on my Macbook which has plenty of storage.

But I got the warning: “Insufficient Space. There’s not enough disk space to send the project to iTunes. About 2205 MB more space is needed.”

I’m not looking to airdrop transfer into iTunes. I’m trying to transfer into the download folder on my Mac so that I can continue to edit the project with iMovie on my Mac which has more storage space.

1. Why did my storage go from 2gbs to zero if no copies were made?
2. Can I transfer the iMovie project and raw video material from the iPad to my Mac via lightning to USB cable in iTunes and then import all that into the Mac’s iMovie app for further editing?
3. Can I airdrop transfer the iMovie project and supporting video clips from the iPad to my iPhone 6s which has plenty of storage? And, if I can do that, can I then transfer the iMovie project and raw video clips from my iPhone 6s to my Mac for further editing?
4. If I can’t do that can I buy a new iPad with more storage and then airdrop the iMovie project and raw video from one iPad to the other and continue editing the project on the iPad with more storage?