I know there are kits out there to turn a barrel or 2 into a wood stove for heating garages. I've seen a couple of the double's in use before and they are pretty good, but the top barrel is pretty high off the ground. I thought about using a set up like this before I built my UDS.
If it is properly vented via chimney outside of the building and the fire doesn't smolder I think it would work. The hardest thing would be to actually use it for smoking and heating at the same time. Normally when you are trying to heat an area you want the fire blazing.