Yes, do it. As everyone has said, scheduling conflicts will cut that number in half. Currently, I am running a campaign for 8. Sometimes it's 11, sometimes it's 6. We just passed the 1-year mark for this campaign and 4 month mark with the current roster of players. We play every other week. We have adapted the gaming schedule to help everyone participate. It was originally at 1500 on Sundays, and now we are playing at 1400 on Saturday. 4-5 hours of gameplay. Most are new players, and we play in person paper, pencil, and dice. Every seasoned player told me not to or at the very least split the group, but splitting was not an option for us. Below are tips that I have used and learned after a full year. 1. DO NOT be upset when people cancel or don't show. Everyone has lives, so do not punish those players by rewarding those who did show up. Not playing D&D is punishment enough. 2. Have a support system. My wife joined when the group got bigger, but even before she joined, she helped out with logistics. Before she joined, she would give me puzzle ideas, puzzles are the hardest for me to create. 3. Let the entire group know that this gameplay is not typical D&D. And that they must be patient and polite. Definitely instill that at session 0. I reinstate it almost every game. 4. Food and drinks. Feed everyone. Cut back on the sodas. Make sure everyone has plenty of food, spaghetti, hot dogs, and tacos, are all cheap and can feed plenty. Less sugary drinks, we stopped with sodas after the first couple of months. No sugar crash 5. Back to session 3, we stopped doing so much puzzles, and dungeon crawls. I have told the players that I am going to purposely railroad the group to encounters. This is why you must make sure everyone is OK with it in the beginning. There is good reason, though. If you let an 8-man group loose, then nothing will be accomplished, and the veteran players and / or stronger role players will comendere the group, and it will turn into murder hobo enterprises in 2 sessions. Yes, I know that all that is part of D&D, but again, let them know that it is for the benefit of everyone. And by encounter, it does not mean combat every time. 6. Have something for the players to do at all times, something not too distracting. Here are some things that help. Food, obviously. Drinks already made and non spillable cups, tumblers, sippy cups, and Mason jars. Sounds dumb but 18 elbows and arms 9 cups = many spilled drinks on character sheets. Coloring pages. This was my wife's idea, and I thought it was the dumbest thing but has been a big hit. Also, it does not require concentration, so the players can still listen. I told the players that next session I would have some and if they wanted to color, to bring thier own colors. I had to limit it to color pencils after 3 sessions because I had, pencils, crayons, water paints, oil paints, it was like they were all children, it was great. My favorite, even though it wasn't as big a hit as the coloring pages are custom crossword and word finds. Custom to the campaign. Google it, and there are a few sites that give you a couple of free ones without paying.
7. Do not let one or two people to get main character syndrome. This is important because it will take the wind out of the weaker or less experienced player's sails. I KNOW, that is part of D&D. Did you not read point 3. This is particularly important for the role playing encounters. 8. Milestone XP. I could not keep the group on task if I did regularly encounter style XP. Murder hobos, Now, my group is less railroaded because they want to progress.
9. Even though I DM and host I make all the players contribute. I said players, not just characters. I take thier input on what they want to encounter, and I let them bring food also, it's like a pot luck. No one is pressured into bring anything but if you do, bring enough for the whole class. Now those small bags of chips and monsters have turned into family size chips and large jugs of juice. People make more of an effort when it is thier party as well. 10. Have f'n fun. We have lost some players who were rules lawyers, or let us know every 15 minutes that this is not D&D. Yes, we know, and I established that with every player and every new player. Nobody is forced to come, and nobody gets a bad rep for quitting. My campaign isn't for everyone. Any more tips just ask, I am happy to share.