How large can cast iron cooking pots be?

Agri Supply sells a 90-gallon cast iron stew pot made by Carolina Cooker, as of 2015. It is 26 inches deep and 42 inches in diameter across the top. The Agri Supply website offers other Carolina Cooker cast iron pots ranging in size from 4 gallons to 90 gallons.

The 40-, 70- and 90-gallon pots come with removable, 3-legged stands for cooking outdoors over a fire. The smaller pots have three 2 1/2-inch attached feet for sitting in hot coals. For indoor cooking, Fine Cooking and The Kitchn state that the most useful size is a 5- to 6-quart cast iron Dutch oven. It is large enough to roast a whole chicken, bake a loaf of artisan bread or cook a large batch of stew.