Just as an offside to the discussion, you were noting about the size of raven rock or site r as its currently called in reality, and in reality its not that big, in fallout 3 you would expect it to be alot bigger as you say to hold civvies. And no idea how much of canon the fallout bible is, but it says that the vaults and such are larger than portrayed, they hold 1000 or so people but you dont see that many or accommodation for that many but you take that into account due to the limitations of the game, and i dont ive seen a game yet that has anything in full scale, last game i remember that actually had full scale outdoors, so when your vehicle got destroyed you had to walk the full distance back to base as you would in real life, so in one case it took at least 4 hours min just walking, some times 8 hours.
The largest bunker that was listed was in England and was released in the media when it was decommissioned as the continuation of government bunker it was basically a small town underground and it was huge.
http://www.bbc.co.uk/wiltshire/content/articles/2005/12/14/burlington_nuclear_bunker_feature.shtml, worth a look at to get an idea of what a bunker in fallout would be, maggie thatcher cut funding to it during her administration, so it was left till they decommissioned it.