I wouldn't try to use a 3" stove like that in your place, but a 4" version with minimal mass to mitigate instant heat and stretch out the delivery by a couple of hours might work. I would build the whole thing outside, testing variations on size and volume and area of different parts to get it as good as you can, and then move it inside. A 4" version of a J-tube is going to need feeding every 10-15 minutes, but tending it for a couple of hours might keep the space warmish for half the night. If parts are 4 or 5" of
cob walls encased in a metal shell, it might even be warm until morning. I would be sure to run the exhaust straight up to get all the draft you can.
Batch box technology (which didn't exist at the time that
thread started) might be able to get a really useful
RMH in 4" or slightly smaller size, at the cost of distinctly more complex and exacting build requirements. See
batchrocket.eu for details.