If we wanted outdoor, we could use BAG as well. Oven inside, grill for those who go that route, and any other plug in item that can be used. Then have some coolers outside for..... wait for it...... wait for it..... BEER! OMG, Beer & Pizza!
Also, I wouldn't suggest cooking more than one pizza in a regular oven at one time. You skew the time it takes to cook and none of these pizzas should share the same baking qualities. Every component dictates a different need for cooking time and temp. PLUS doing one or two at a time allows small samples to be had over the time frame and no one filling up too fast!
Outdoor Rock Band the same day?