1%
The person outside Remy's cabin waited for a while until yet another person appeared and then politely knocked on the door. Remy opened and welcomed his guests, but the three exchanged no words.
The three descended into the basement and each of them entered one of the rooms with the unusual environments. Remy entered the one with a lava pool and began setting up some kind of formation, while his companions did the same in the freezing room, and the room with dirt.
A few hours later, when they concluded their work, the three entered the fourth room that happened to be completely normal. There they worked together to finish setting up the formation which, when finished, created a small Minor realm around 2000 square feet large.