Rocket Stove in Bus

My bus is my home. It gets to 0 fahrenheit here. I want a rocket stove as backup to my propane heater. It might need to be more like a rmh though or a hybrid. I'm thinking fire brick and adobe with metal chimney. I'm hoping to stick to j type rmh principles. Any advice appreciated.
Edit: just delete nobody will answer this bs.

Is the bus going to move again?

If not you could put the burn chamber out side and thread the riser through the bus to exit at the top with a small bell stratification chamber to extract the heat.

Do you have pictures and dimensions of the bus?

If the bus is guttable, then one could even imagine a Kang underfloor heater so you only lose vertical height and not horizontal space. And then cook outside in a tent with the waste heat heating your living space.