[@Crusader Lord]

So there is Green around the test-site but the facility itself isn't currently suffering any major growth. I suggested Searchlight since it is irradiated and that would provide a level of protection that the mutants would be able to use. 

I'm not opposed to some of the Remnants banding together but I would want a good explanation as to why. In-game it is very difficult (80 speech check) to convince all of them to fight for the NCR. Even when convinced the game makes it clear its a 'last hurrah' and they retire after the battle. The Enclave remnants are essentially wanted fugitives of the NCR so they would have to operate with the utmost discretion to avoid bringing attention onto them. Likewise, this RP takes place 7 years after the events of FNV. So I'd say that the remnants would be at the youngest early sixties, oldest mid-seventies.  

I might suggest incorporating the Bright Brotherhood into your faction. Perhaps with a cure Dr. Henry is able to negotiate a truce between them and the Nightkin attacking the facility. Then he is able to help them activate their rockets and complete their journey. When completed successfully the 'Come Fly with me' quest has the Bright Brotherhood returning to Novac to evacuate and rebuild the settlement after the Legion's attack. This implies they are able to form relationships with other factions and they don't travel too far away.

While I think a relationship with Novac would be possible, in-game it is stated many people in Novac survive off scavenging the Repconn facility. So if it is occupied there should be some explanation as to how that conflict is resolved and if not, then have that be a conflict in the RP.

Hope this answers your questions, please let me know if you have anything else you want to ask. Excited to see what you come up with!