Will small work? Does size Matter?

So, I get the idea.  As long as I can maintain fire no reason a smaller unit would not work just fine.  And charcoal will slow burn a long time.

I got a new grill last year and still have the old one.  It's actually just the right size about 3 sq/t of cooking surface.  The Top which goes up and over from the back to the front handle is sheet steel.  The lid actually seals well.  If I take out the burner guts, there are already supports in place for a steel plate for the smoke to flow under.  The sides and bottom however are aluminum.  On the top the steel presses into a channel in the aluminum sides.  I could cut a hole in the top and weld a steel stack in place but cutting a hole in the bottom on the side which is cast aluminum is a different issue.  I guess I could cut in a hole and then bolt on a large pipe flange screw that on to a pipe and weld that to  a steel fire box then bolt the flange to the aluminum.  So many possibilities.  Nothing like building things out of free junk which will make great food.

Thanks for getting my thinking on track.