Per CNN, Life At Sea Cruises now offers "Cabins [that] run the gamut from 13 square feet..." That's a little less than a 7' x 2' cabin they call their "virtual cabin." I hope this is a typo on CNN's part, or that's just room for a tiny bed!
See https://www.cnn.com/travel/article/3-year-cruise-mv-gemini/index.html .