GreenFrog, I have an older Snowtrekker 8 x 12 Exp Crew tent that I now use as my "solo" tent. Here is a link to a video of it showing the interior space with 1 cot. You can easily fit another cot on the opposite long wall. Maybe even a third cot, lengthwise, in the middle but I would suspect that all the cots would be touching each other. I've easily slept 3 comfortably on the ground before and below is a pic of the set up for two on the ground (2 Syn Mat 7 air mattresses) with ample room on the outside walls for gear. The bottom left corner of the photo is the stove area (pic below) and the bottom right side is the prep/chef area (pic below). This might give you more of an idea of interior size and room you might need in your tent decision. In my opinion and for what you are describing how you intend to use it I'd go for the 9 x 11.5.