Brad, the ability to bake pizzas back to back depends entirely on the material and thickness of the stone. The thicker the stone, the greater thermal mass, the more heat it can store.
The Emile Henry stone, unfortunately, is inferior in a few ways, one of which is thermal mass- at around 1/2", it has very little. If, say, your first pizza bakes in 8 minutes, then it might draw enough heat from the stone to result in a 12-15 minute bake on the second pie. Some styles can handle longer bakes, but not NY. A NY style pizza that's good at 8 minutes will be really crappy at 12-15.
Thin stones give off most of their stored heat during the bake. The only option is to pre-heat the stone again- you won't need the full initial pre-heat time, but you will need some time between pizzas.
Or, you can get a decent pizza stone.
