I like the idea, and I pretty much know that it's *possible* to pull off something of such a big scale. Especially if you can also keep each little thing as simple as possible.
But my concerns are these:
- Do you have the endurance to actually pull this off? Of course, at this point in time this question isn't all that relevant.
- Will there really be 6 to 10 or more people who have that much time? Essentially option 2 above.
- Can 6-10 players actually play for that long without anyones game crashing?
- How much bandwidth will this mission require, for each client? Do we have (stable) hosts with that much bandwidth, for that sort of duration?