Is there a way to save recent files to the iPad to work offline? Is iOS supposed to this automatically?
Regardless of the size of the storage on your device the inability to mark selected files or folders for automated sync renders it useless when travelling and there’s no inflight WiFi.
I don’t think there is a way to make it save files automatically, but I’ve been very pleased with Microsoft OneDrive for things like this. I’ve moved all my files to it, and I have folders marked for offline access. Some of these I have saved offline all the time, others I’ll dynamically choose before I head out for a trip.