actually, as far as I understand, three endings offer you 6 months to live (decline Arasaka's offer, take Rogue's place, leave with Aldecaldos).
this is why I now think a DLC, if it happens, will start the same way the game started - you'll have a short introduction into what's happened since the ending and then thrust into another story in NC (I guess the nomad ctrl-V will have to come back)
For me there is no option to leave NC as a place that is a setting for whole story. Cyberpunk is Nightcity. It's like Batman going to Metropolis City. And second - CD77 just put to much effort into builiding NC.
This is different world than Witcher. There was a big world with characters that were know for moving from place to place. Here? Nope, it's go completely against the lore.
Multiplayer can take place as a new charakter, but we still have an elephant in the room with V.