Time delays are the major difficulty
Perhaps instead of linear video logs, they could use "choose your own adventure" style updates? The sender would try to anticipate the kinds of questions and scenarios that the nauts might have, then package up all the data into something like an Infocom or SCUMM format for playback in a non-linear way up on the ship. They could also have Max Headroom-style virtual actor software (complete with tunable voice synthesis a la Hatsune Miku) sent up with them, so that the nauts could interact with something that looks and sounds something like the people back home (all without wasting valuable transmission bandwidth).
The CYOA games that they send up might have a bit of replay value, too, and would give people a bit of entertainment value (both watching/playing and crafting their own modules to be sent back) for the long journey.