I don't personally know of any such cheats/hacks, but if you don't care about a party score or the (IMO) lame "honeymoon" thing after throwing a good wedding party or filling a "Throw Wedding Party" want or what-have-you, you can have it as a for-fun outing instead of a party and then it can last as long as you want. That's how I do it, when I bother with having a wedding at all. Makes it a lot easier to have it at a community lot, too, which is what I usually do, along with teleporting a whole lot more guests to the lot for the big day.
I don't know if there's a mod like that or not, but I wouldn't be surprised if there is. You'd probably have better luck asking about that on the Where Can I Find forum instead, though. You can find that forum here: http://www.modthesims.info/fd.php?f=556 Good luck!
Batbox! Once the party's started, there are several party options on it. Extend the timer, fulfill the conditions, destroy the party controller--of course they aren't called that, and I've only used the last one, I think. (Idiot guests all ran off to class two seconds after the graduation party started.) I don't remember ever using the others. Seems like most parties go on long enough for the host to be tired or need to use the bathroom or stinky as it is.