I used to live in a 384 sg ft dry cabin in Alaska. The outhouse was very chilly in the winter. That thing used to echo because I had no possessions besides my clothes, a rudimentary cooking set, a TV, some books, and my bed (a pile of blankets on the floor).
Right now we're living in a 780 sq ft apartment and it FEELS like a tiny house with a dog, two cats, and my husband. He also is a video game and tool collector, so it feels like we have even less space, haha!
I do like that it's easy to clean, though, and it's forced us to be really really selective about what we bring into the house now.