Perhaps look in the Repository directory, this is where it caches these downloads when online.
If these "rural school" machines have networked drives the large files can be pulled from machine to machine, or you can burn some DVD's to distribute content via mail, sneaker-net, etc.
The "No Internet" trade here is that you're going to have to get substantially more aware of what the tools do and expect, and where they put things. Most all of the "From Internet" can be done "From Local".
Perhaps there are notes, or user experiences, from corporate fire-walled systems completely disconnected from the internet. A lot of schools/colleges do this to limit malware and such, so I'd expect there to be resources and experiences out there that you can draw on.
