How do I edit GoPro videos on my iPad,on iMovie when I do not have enough storage to save them on my iPad

So i recently purchased a gopro and im interested in making movies etc,when I ran into an interesting problem.I know you can get videos on your iPad from your GoPro wirelessly but that's through the GoPro app and I need to get my videos into the Imovie app.I also know you can save the videos on your iPad to bring them to the imovie app but I do not have enough storage to save even a 20 minute clip to bring it over to the iMovie app,so how do I get them to the iMovie app and then to an external hard drive from my iPad without a computer? Is it possible?