My Glacier bay wood stove is about 24" square and except for the cast iron doors is 1/4". The stove is over 27 years old and has had some long long hot fires it it. It is firebrick lined in the floor and 4" of each side but shows no sign of any deterioration or extreme wear...for what it's worth
Make no mistake, there ain't no powder in this Puff ! And... I'm not really a crazy person but I play one in real life
Just a little note to think about. You said thicker than 1/4" for the floor. I'm sure all of us on here have some sort of wood rack inside the firebox. I actually bought a wood rack that goes into a fireplace. Heat rises, and outside fresh air gets pulled in and under the fire. The bottom plate on my firebox is 1/8", and I can almost put my hand on it. It gets very warm, but not hot enough to scald you.