Right now, I have a small hibachi, which is good for one or two people. In the future, I'd like to get a larger grill. Ideally, I'd like something dual-fuel, but my main concern is what size grill to buy. Is there a specific formula for calculating the cooking space needed for each person? If so, does anyone bother with it? I think it would be nice to be able to cook more food, as well as a variety of food. Even with one or two people, I prefer to do all of my grilling at once, rather than be constantly firing up the (charcoal right now) grill, especially in the hotter or otherwise inclement weather.