I'm in the same boat as Flatt, as he makes a good point. I think, when the round ends, it gives a Crew Transfer Vote, just like what happens at the 2 hour mark during normal shifts. If, lets say, worst case, 20 people died, then vote goes through, Crew Transfer happens, and rounds over.
If not, then Round Continues like normal, possibly having an earlier Crew Transfer vote (I don't know, something like an hour, hour 1/2 maybe?) then, it will extend to 2 hours, and then it will be back to what would be considered "normal".