Certified GKH Gardening Expert
Depending on which type of elephant year, you may want to start small. Some elephant ears, like Alocasia, grow very slowly. A large container would potentially promote rot and overwatering in this case.
If this is a Colocasia type, then a large container would not be a bad idea, as long as it was a fast growing cultivar.
Either way, it is usually best to start small, and pot up to a container only 1 or 2 inches larger on all sides each time you pot up.
These articles will help you to care for the most common two types of Elephant Ear: