Transfer mp3 to iphone while not at home

I'm at a sound studio and record a new song, that I want to listen to while traveling home. How do I get the large (100mb+) mp3 onto my phone, when I don't have my private computer present?

Some have suggested sending the file through email and opening that message on my iPhone, but then I can't play it without internet access.

The only way I have been able to do it, is to use the Downloads Lite app

https://itunes.apple.com/us/app/downloads-lite-downloader/id349275540

Save it as a file, and open it via another mp3 player like Djay:

https://itunes.apple.com/us/app/djay-for-iphone/id424492403

While this method works, it's a bit complicated and the song is still not loaded into my music library. Is there not another easy way to save a tune on my iPhone when I'm not at home?