Self-storage, the basic primer
Also, reputable companies that will give you additional containers but you only pay for the ones you will use. In other words, there is no need to worry about ordering less than what you might actually need or for being charged for unused containers. Then after filling up the containers, you can just call the company again for pick up. They will then move them to one of their storage facilities or to your specified destination at your most convenient time to receive them. Or you can have them kept temporarily at one of their storage facilities.