I have an REI Quarter Dome 2+ that fits myself and my LW (long and wide) Exped air mat, along with my pack at the feet of the air mat, without issue. I should mention that I'm 6'4" so I feel your gigantic pain. I also manage to squeeze in my dog when it's just he and I versus myself and my girlfriend.
Actually come to think of it, the dog manages to squeeze into the tent even with her, I, and our two air mats. D*mn that dog is spoiled.