I wanted to talk a little more about what I mean when I say "short campaign" and maybe give an example or two.
First of all, I generally mean the opposite of an "ongoing campaign." By this measure, most of the D&D adventures would qualify, except that a short campaign, IMO, should max out at say 12 sessions. In addition to length, there is the issue of what makes a campaign a campaign, versus just an adventure. I made the analogy in the OP of a novel versus a short story -- multiple storylines, important subplots, and character arcs for more than just the protagonist -- and I think another analogy would be television in the vein of Buffy: monster (or dungeon) of the week, with a throughline. Any given season of Buffy, Angel, X-Files, or similar shows would be a good "short campaign." With this in mind, the only WotC adventure I would call a "short campaign" is Dragon Heist (which is a bad adventure but good toolbox -- but that's a different discussion).
I used to go visit friend in Pittsburg after we all moved away from Savannah, GA. We would cram 36 to 40 hours of table time into a 4 or 5 day weekend (we were young) -- which represents something like 9 to 12 "normal sessions" worth of play time these days. Because that only happened a couple times a year (then eventually one, and finally none...) I ran short campaigns each time. Many of those were portions of what was a larger mythology, but once in a while it would be something totally separate. One example of the former is the Golden Age story of our D&D world turned Super Hero world. One example of the latter is our Mutant Future "tomorrow project" weirdo mashup thing involving actual angels and forgotten weapons of mass destruction. In either case, I built a framework for the campaign and player choices, random tables, and alcohol fueled spur of the moment creativity defined the campaign.
I took the skills I developed here to conventions with me, running 4 or 5 session mini-convention-campaigns in the much same way (often with slightly more structure and slightly less alcohol; but only slightly). Sometimes these run more like extended adventures or separate episodic scenarios, but often times it has the sense of campaign to it -- and I have players that sign up for those games for that very reason (because they don't have a regular campaign and only get to play at conventions). A good example of this set up is The Valley of Tombs, a place full of small dungeons signposted with difficulty levels (thinly veiled so as to be in the fiction) so the players could decide their risk versus reward. Another was Return to the Isle of Dread (exactly like it sounds). As usual, I rely on the players and random charts and my own inspiration to make these events into campaigns of a sort.
This summer, I am planning on running a short Daggerheart campaign to really put the game through its paces and see if there is any there there, I am not sure what I will do with it yet, but I am looking forward to that as my next short campaign.