OK. My Oslo is in a room that is 20 x 24. But an extremely high cathedral ceiling, with a loft, the log walls are 11 feet high.
To the peak of the ceiling from the floor is 22 feet. Very tight and well built great insulation.
Most of the guys said the Oslo would be too large.
However, my place is actually 2 log cabins joined together with a dog trot. The dog trot is 12 x 14. I built it where there is one step up to the dog trot, and one step up from the dog trot to the original log cabin. I did this because heat rises.
From the cabin where the Oslo is, the door opening is 4 feet wide and 8 feet high. The door from the dog trot to the original cabin is 8 feet high, and 4 feet wide. All this, so that heat will move out of the wood stove room and in to the rest of the house.
It works great.
I think the Oslo would work for you. I don't want to get you in to trouble, if, God Forbid, you had a fire, it is possible that an insurance investigator might call you out for having a bandit corner install on the Oslo, and refuse to pay. I don't know how all that works.