Well, if the bayou was 5 miles across and the frog had a torso diameter of 7 miles, the frog would overhang the bayou by a full mile on two sides! This seems unlikely. However, if the volume of the of the bayou was 1e12 cubic feet (used Bartholomew Bayou and assumed an average depth of 2 feet) and the volume of the average bull frog was ~ 0.02 cubic feet (calculated in two ways, 0.5 feet *0.2 feet * 0.2 feet or 17 oz (typical bull frog weight) to cubic feet, these are both rough approximations that don't take into account specifics of the bullfrog shape or the bullfrog's specific density). Anyway, that would imply that the maximum number of bullfrogs in the bayou would be 5e13 and that no more would fit. That's a LOT of frogs. However. it does assume that the frogs are packed in the tightest formation possible. A closest froggy packing structure if you will. So, I would say something like 1e13 would be the actual max number of frogs in this particular bayou and no more would fit. So, the implication is that unfortunately there will be a maximum number of that would fit in Tiana's bayou. Another thing that is not taken into account, is that an attraction actually used the maximum number of frogs (sculptures and animatronics in this case) would probably alienate people who had frog phobias or people who wanted to see main characters from the movie. However, the characters could appear many times in frog form, but this would be weird for all but one character. Even then, you'd have to be at the correct point on the story timeline.