As for room, we currently have myself and 4 other players, but we don't always have all 5 people every week. The reason why we're looking for more people is that we want to have more consistency -- often, when we only have 2 or 3 people, we have to cancel the game, which isn't much fun for those of us who planned on playing.
I'll ask the DM how many is too many. I'm sure we can accomodate at least 2 more, and honestly, I'd like to have some female gamers in the group for some diversity.
When you email me, I'll give you more info on when we meet, the current status of our game(s), etc.