Depending on how familiar you are with Fallout lore, I have a few different ideas. One, I had written up months ago that was going to end up being a DLC-sized mod if I ever bothered to learn Creation Kit, would involve the ruins of New York and a few new factions. Another, basically playing through OC’s surviving in the world, maybe in the wake of big events like the end stories of games. Anything specific you might want to try?