[Fallout] How will the Wasteland look in 100 or 200 years?

Let's say all good factions(NCR,BOS,Minutemen) manage to stablize they're territory, and get armies to the size of the U.S in it's prime. How will the Wasteland look in 100 or 200 years(let's also say that the Sole Survivor gives every faction leader the mysterious serum and now Kimball, Maxson, and him/her can live for hundreds of years