Wait … I thought you did the backups.
Using the Simple Pomodoro App on the iPad works well (for me). I connect the iPad to the MacBook Pro to ensure a continuous power suppy. Might sound inconvenient, but this is a boon. The connection not only provides power, it can also be used to transfer data. Some Apps allow you to transfer data directly on the iPad via iTunes (e.g., Good Reader, File App Pro).
While not a permanent solution and unsuitable for large files, it’s probably a good idea for the document you are working on. Just close it first. Compressing the file might also be a good idea, as you can then rename the compressed file to include the date.
How was it, better safe than sorry.