Awesome. I've done ten before and it's not a problem, despite what people say.
Splitting isn't always an option, because real life sucks.
Anyway, here's my recommendations:
- Give each player a job. One is in charge of keeping track of spell durations, another is in charge of soda, another does hit points for the enemies, another takes notes, etc. Remove as much extra burden on you as possible.
- Use email. If two players want to debate whether to kill the goblin children, tell them to figure it out out of game, not in-game.
- Push for speed. Have people roll damage with attack rolls, don't let lolly-gagging happen on combat rounds.
- Stay on Topic. In my experiences, it's harder to keep a larger group on task, and staying IC. Recruit a player to keep people on task.
- Players see the damage they've done. This was key for my games, which is why I mention it again. Letting them keep track of hit points lets them know exactly how much damage they've done. It lets them estimate how tough a guy is, and see if he's healing, if he's got DR. It's great to want to "hide" that info from players behind a description, but that doesn't help speed up the game, or facilitate easy play, so don't bother hiding it. Just let them know, "your weapon doesn't puncture his thick hide as well" and say "subtract 5 for DR" to the hit point recorder.
- Drop the books. For all intents and purposes, you're the DM still. Set up with the players that during the game, you'll adjucate effects based on the situation to speed play. Don't look at the books - just guess at what it is, and I would tend to favor the players in most cases. If afterwards you turn out to be wrong, admit it, and move on. Now, one game I had, the players communicated enough that the person in charge of spells looked up a spell just after they had gone, so they could tell me the effects right then and there. Reward that, as it helps everyone.
It's definitely doable. Look at where your game is inefficient, and fix it.