When we were building the cabin where the majority of this construction is taking place, the floor we had just put in was called the dance floor. Mostly because it was a big surface with not much else going on.
I also scavenged a door from the basement storage of the cabin. We had brought it up to do a better cut down job to replace the one that is there already. (The basement is really an oversized crawl space. I have to keep my head ducked or a -lot- of swearing is in my future). I am not happy with it as a final solution, but it will suit for getting spacing, and even getting me through the lock up stage of the tiny house. (I really want more light in that side of the house and a window is the door is more optimal).
If I get really enthusiastic I can always try cutting it in half and making a dutch door.