Most of the iTunes U courses for programming, in particular, the Stanford Edu and the Carnegie Mellon series are easily loaded on an iPad that may be solar powered/easily charged in remote locations.
However, it is recommended that you get the absolute maximum storage to hold all the video/audio/app/e-book content.
Avoid courses requiring a remote login to proceed since you are not able to communicate.
GSM capable is suggested, unlocked iPad 128GB which usually equates to AT&T for the carrier. But do make sure it is unlocked first and before you even start loading the courses.
Load all the courses at the absolute fastest Internet location, my suggestion is a major bandwidth hub with 1 gigabit or 100 megabit minimum and be prepared to campout a bit to get all the synchronizations finished up.
You can also choose to utilize iTunes itself, but the iPad is where you need to make sure the content is complete, so a PC or better yet, Mac with iTunes and lots of storage on tap is the ticket for best results.
Budgeting space is significant as well plus other topics may be great.
Linux? Well Linux would work, but far less elegant than iTunes U notebooks and iPad combination.
Last but not least, encase the device in a robust container for protection, here is a listing from Redlands in Australia to review:
These are the iPad cases we recommend at the College.