However, if Benny was a bit more thorough in his post-mortem, if Victor was an hour too late digging you up, if Doc Mitchell was too emotionally traumatised from the relentless taunts of the Weintraubs - where would that leave the Mojave, after Hoover Dam (which is destined to happen whether the Courier survives or not - Caesar's Legion would never leave the NCR alone).
My own view is that Mr. House stands a pretty good chance of coming out on top. All he needs to do is recruit another agent, which could be easily done with his army of securitrons monitoring the Mojave. The NCR and Caesar's Legion, having to do without the Courier's help, would beat the ever-loving crap out of each other in a much more closely run thing. I think the battle is too close to call; possibly a Pyrrhic Victory for the NCR- Kimball would be dead, the fiends would attack their HQ, their monorail would be destroyed. Caesar (possibly dead without the Courier - although he has a bit of a Schroedinger's tumor - there and fatal in his questline, just there in any other) would put up a good fight with Lanius's battle command.
With both factions significantly weakened, all House needs to do is instruct his agent to slip on a Stealth Boy, Infiltrate The Fort, retrieve the chip from Benny's crucified self or Caesar's comatose body and upgrade the army. A tall order, but Mr. House is a patient man.
Benny is still too stupid to pull it off by himself - likely still getting himself captured and strung up when he senses the excrement is about to hit the fan.