Well, if you're soliciting suggestions, which I can only assume you are since you're musing about this publicly on an open forum with an oh-so-tempting reply button, I have some thoughts...
You largely can ignore the trials and travails of getting the whole shindig organized and set up unless it presents something significantly differently than what we saw in Clarion Call. We've done all that and don't really need to see it again so soon. In particular, Utena and Corwin's pre-wedding jitters probably don't need to be re-visited. I would maybe focus on two things...
1) What are the specific hurdles of getting this thing set up on Cephiro that weren't already covered in Clarion Call? Mine that for content. If it's just "this is the same problem we had on B6, merely transplanted to Cephiro" it probably isn't worth showing, but if it's "this is an issue that is unique to the venue" than there is value in putting it on-screen.
2) The ceremony and reception.
Number two is the big one. We didn't GET to the actual ceremony and post-ceremony party in Clarion Call. That will be new and exciting, so roll with that more than the pre-wedding logistics. For that matter, if it were me writing this (disclaimer: I am in no way equipped to write this) I might consider not even bothering with a run-up. We've seen all that before. I'd consider making the first two paragraphs the exchange of vows, pure in media res, and then roll from there into the rest of the ceremony and the reception.
I would also submit that it's totally okay to NOT show things. You make an explicit analogy to large battles. Well, there was a large battle in First Dates and Firefights... and you didn't show most of it. Hell, the fight in orbit around Tau Ceti was arguably the most important part of it, and it barely figured in. And that was okay! It worked great. We didn't NEED another five thousand or so words about starships blowing up.
So don't be afraid to leave scenes on the cutting room floor. That's what Featured Documents are for. People who want to know how the orbital battle at Tau Ceti went can consult Utena's after-action report. (There's an argument to be made that Featured Documents of that sort should be linked to from the piece of work they're relevant to, but that's another discussion.) It's totally okay for stuff to just NOT be shown, especially if they feel like they're bloated and unnecessary or very "same-y." The crowd control that's taking place behind the scenes can remain there unless it's something actually, you know, interesting.