@rdanhenry - You get what I was thinking when I mentioned using a Caravan in the first place. What you call 'options' I was calling 'chapters' which anyone of us could create and it would become a possible choice for the GM.
Originally, I was thinking more along the lines of (most of these are just made up on the fly):
Chapter 1 - "The King's Cup"
<the main adventure we are currently working on>
Chapter 2 - "A Marriage alliance?"
A princess is being escorted to her new husband to be. Against her will? She along with one of her Guards vanish in the night. Was she abducted? Did she make a run for it with the man of her dreams? Who will track them down or will the savage tribes of the land find them first?
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Chapter 7 - "Of Herb's and Herbalism"
In this option there is a group of Herb collectors that travel with the caravan pawning their wares from town to town. Along the way they forage wherever they can to supplement their stock. Unfortunately, one of them was bitten during one of these forest forays by a strange wolf. He has now become a werewolf and as one by one members of the caravan come to a nasty end it falls upon the party to somehow stop the Caravan of carnage. ...
Chapter 8 - "The Theives of Greenwood"
The Caravan is robed by men of the forest..whatever..
And so on and on with each section having it's own encounter maps and such. Thus, when a GM sat down to plan out a gaming session he or she could just add in as many as they want and basically leave it up to the PC's to choose what they wish to do. Of course, it's always nice to have an overall story that fills the main flow of the game but this would be a great supplement in my opinion for almost any GM. And if things were going stale they can always have a new group (aka "chapter") join at the next town. Some chapters could be quite challenging and used at the GM's discretion based upon the PC strengths. How about, "Chapter 12" - "Dragon Roast" :O
Almost anyone's ideas could be incorporated but the problem is, this could become a HUGE supplement.