Okay, so, i was just sitting in my house, when i thought of this. Okay so, you know how NCR troopers always say "Patrolling the Mojave almost makes you wish for a nuclear winter" Well, what happens if there was a nuclear winter(btw this DLC would come out near Christmas time)and New Vegas' supplies are low and all the power is cut, so you need to go and find shipments of supplies in different places to get most of the citizens through the winter, i.e maybe your character has to travel to New Reno to get something to put the lights back on back in NV.
Just a thought, im new to this forum so bear with me:)