I'd be willing to do it with four. Turns go by quickly in OCC.
Just as a note, I ran a preliminary OCC with the same parameters as what we will be doing, and here are my thoughts:
We cannot stay friends with everyone. Or rather, we can try, but it will screw us to no end. We will have to *****slap somebody at some point during the game, if only perhaps to cripple them and get tech for peace. How we go about doing that is another issue.
On a related note, beware runaway AIs. They happen, even on Prince. Even on Warlord.
Our tech priorities in the early game are to collar one or two religions, get worker techs, and start trading with AI as soon as humanly possible. Beeline to Alphabet. Then we can go back and pick up the Ancient techs we missed.
CULTURE CULTURE CULTURE!
GREAT LEADERS! PACIFISM WILL BE OUR FRIEND!
Pray for a good die roll with resources. I had great Ancient Age resources (Iron, Stone, a deer, and sheep), but I had literally NOTHING ELSE. It SUCKED.
Also, I think there might be an issue with National Wonders. The game was allowing me to build more than two in my city. Wasn't sure if the effects stacked or not. Anyone know anything about this?