So solution #1: Sell iPad, buy Laptop
Other solution: take his iPad home, fill it up and bring it back.
Solution #2: Buy second iPad.
not what I call excellent solutions
Your problems being.
(1) You can't take the iPad away, as you only see him once a week.
(2) No internet access in the hospital.
That means that you have to take the movies / tv shows to him on a device, and load them up there and then. The easiest way to do that, as previously suggested, is for you to take a laptop, or laptop with external hard drive loaded with media, to his room.
That way, you can connect his iPad, and download what he wants there and then. Other than that, replacing the iPad with a laptop seems a far better solution, because you would be able to keep swapping pre-loaded external hard drives for him.
Another thing to consider. If you load standard def films on a 64Gb iPad, say 1Gb/film = maybe 50ish hours. Would he watch that much in a week?
Not an answer to your question, but might I suggest perhaps load some iBooks too.