Believe it or not, TiVo has required that iOS users stream recordings on WiFi for the past seven years. Yes, despite the rise of fast and (theoretically) unlimited mobile data, you couldn't catch up on shows during your commute. Reason has prevailed at last, however. TiVo has updated its iOS app to support cellular streaming, letting you watch live and recorded shows as long as you have a solid internet connection.
There are still catches. Dave Zatz warned that the approach remained "a bit kludgey," and that you can't skip commercials like you can on your TV. You do avoid pre-roll ads, though, and this beats having to track down a WiFi hotspot to watch an episode. Streaming services like Hulu theoretically fill this gap for many people, but this could be extremely helpful if you still have a conventional TV subscription.