Is it possible?

There's really no way to tell how long a game will take. I played a 1v1 game that took 4 hours on a small map 16 planets 1 star cause not only was there a pirate base choking the lane to eachother, bye the time we got threw them we both ended up with such big fleets we were at a stand still for awhile till he decided to have like 5 shipyards pumping out ships while I was only using 3.

Then there's the 3v3 that took less than an hour cause the other team was expanding as fast as possible and our team slowly expanding just did the rush tactic since it was a medium map anyway.

I guess it all goes on how large the map is, number of stars, and the stradegy of play everyone is using at the time.

In my experience, most 3v3s on the large random single star map don't last more than one hour and 45 minutes, at which point the game will have already been decided. Most games don't end with with the winners conquering the losers last planets; instead the players on the losing team quit say "gg, this one is over" and quit. This is a good thing because it allows everyone to go start up a new game instead of just going through the motions of conquering planets once the game is no longer competitive or compelling.

That being said - I have played some games that go over 3 hours - and they aren't always the huge 5v5 multi star games!!!

I once went for 6 1/2 hours on a LAN, me and one other human on a custom 4-star map with a bunch of computer players. It was interesting to see how the long-term game played out: remarkably similar to Civilization. A couple CPU's got killed early on, a couple lasted longer, a few created respectable 7-10 planet enclaves, and me, my friend, and two Advent CPU's controlled huge chunks of the galaxy.

The end result? Stalemate, and 2 AM rolled around. Neither of us noticed an option to save LAN games, but that would have helped.