My newborn cornsnakes lived in containers that were for food in the fridge. They were 2 inches high, 7 inches long, and 5 inches wide. VERY tiny. But every single snake I had hatch except 1 (1 out of 22) ate on the first try, FT.
Of course a few weeks later they moved up into the world of shoeboxes.....but these small enclosures are really extremely helpful to any herper breeding.