Originally Posted by crazy banana

Bigger is definitely better 😉.
Banana plants are relatively shallow rooted, so if you still want to grow in a container, I would look into something with a bigger surface area other than a deep container.
Have you thought of putting drainage holes in a livestock stock tank? "Tractor Supply Company" offers the foam type which are not too heavy, but they will get heavy once you fill them up with dirt and a nice banana plant. I have seen people doing this here once, but I don't know how successful they were with fruiting their plant.