Short adventures for me are 1 to 2 weeks.
What do you define as a campaign?
You see we have been playing Flashing Blades, for about 7 years now in the same campaign setting with the timeline always moving forward. But we have had breaks to play other games and had changes of characters and players. Is that one campaign, or since we don't tend to play more than 6 months in one go a mini-campaign? Or since that actual 'adventures' tend to be no more than a few weeks short adventures?
Its the same for our high level AD&D, mid-level D&D, occasional Cyberpunk, etc...
To be honest we all get board of playing the same thing for more than 6 months, plus the DM's get fatigue so we rotate after about 6 months of play. I wouldn't say we were playing 'short adventures' however.