I want to run a game in Eberron, but start it on the Day of Mourning (using the adventure in the back of the 4E book), then advance the time four years. However, as I want to use 5E, I want them to use what amounts to four years of downtime. I don't feel it's fair to take that away.
But here's the problem: I know they'll try to say that they continue adventuring, but that undercuts the point of the time skip. I want them to be able to do everything except explicitly adventure. How would I justify telling them they can't?
I initially thought about saying that Khorvaire is too unstable for adventuring to be viable, but that feels flimsy. Are there other reasons I could use?