In my opinion Caesar's Legion was pure gold as a faction. They're not the faction I side with but I love their inclusion in FNV. Even if Caesar and Lanius die (which seems likely, seeing as they are the primary antagonists in all but one of the four possible endings) that of course will not mean the end of the Legion. One or several high ranking member will take the mantle of Caesar and continue their conquests against enemies or even other factions within the Legion, assuming they can't agree on a successor to Caesar/Lanius.
Anyway, my question is this: Do you believe we will see anything from the Legion in Fallout 4? They are obviously not a major power within Boston or the surrounding area and it's a long way from home, but do you think there is any chance they make an appearance? The BoS has sent scouts and patrols east, as far as Washington DC. I'm not sure if Caesar would do the same. Although if you were in charge of a massive army spanning several former US states' territory, you might send scouts into previously uncharted territory as you never know what you could find.
http://i.imgur.com/w0za4Em.png shows the Legion's territory and their distance to Boston. Yet the Western BoS was further away (and a faction with fewer people and resources) and they made the trip all the way east.
In my opinion it is unlikely a Legion victory at Hoover Dam will be canon. If this is the case that would mean the Legion has hit a wall in their expansion westward. Either the NCR will actively be hunting them down from the west or (more likely IMO) Mr House or Yes Man/the Courier stands waiting to smash them should they ever try to advance west again. So if they were to expand or move their army it would have to be north, east or south. Thus it would make sense to send scouting parties, I think. See what's up ahead if they decide to move in that direction. And moving east would put the most distance between them and those who butchered them at Hoover Dam.
What do you think? Is there a real possibility we will encouter any Legion scouts or are these simply the wishful ramblings of a madman in love with FNV?