most phones and tablets both android and ios have a youtube app.... have you considered trying those? i realize they are not "offline" that way, but if you already use a smartphone, you already pay for internet access on it, so why not use it for what you love.
Thanks for the suggestion, yes, I do watch via YouTube, but prefer to be able to subscribe through iTunes. The show might gain additional appletv viewers as well.
Also, there's times when I don't have Internet on my phone, when I'm on subways,etc.