Someone mentioned that February wouldn't be good for them, so I suggest a start time as the first week of March.
February won't be good for me either, because it's carnival season here [Louisiana], and for me that means constant work in the carnival mask business. March sounds good to me.
As a side note/suggestion, have any here heard or played Grimrock? [a modern Dungeonmaster/ Eye of the Beholder clone]
For Grimrock, a bunch of us (forum members) made a dungeon for inclusion in a combined map; where the adventure passed through each on the way to the end. Each modder had up to three areas for their room.
The way this was done, is that we hosted the project on Dropbox, and each modder edited their own parts of it. [not concurrently]
It occurs to me that it is at least possible to do the same in FRUA. Each participant could be allotted three [or more] modules, and X number of chained events; X number of art slots; and so on. An experienced FRUA modder would need to decide a reasonable/practical number of assets for each modder, and decide what assets had to remain unedited, for use by all. The rooms could be isolated buildings in town, encounters in the wild; secret crypts under the abbey, or private castle or events like a circus just outside of town, etc...
**I'm not [necessarily] suggesting this for this current challenge, but [if determined feasible] as maybe the next one. The Grimrock mods [three of them! Full length adventures] were very fun to make and play because each designer only knew their own contribution to it, and because it was a full size adventure; a lot more than what one person could design (and test!) in a week.
If anyone here plays Grimrock, and is interested in a good adventure mod these are the released 'One Room Round Robin' mods for Grimrock 1:
*Two are released, while number three is still in active development.
** The first was release before I'd heard of it, and so I worked only on the second and upcoming third mod in the series.