Imo if the conditions are right then I see nothing wrong with a large container like that. Honestly I almost duplicate my pacman frog tank conditions except I offer more water. Same temp same humidity same diet pretty much. Im not sure what your situation is, but you should be able to find used aquariums for $1 a gallon up to 55 - 75 gallons. If you find a female you won't need a huge tank.

Side note: they're very quick when young be careful moving your hand around in a confined space with one. They're bite is pretty rough at 3" +.