They would have made cloth, primarily with wool, but your overall point is quite valid; clothing is the least of their worries. For example, even if there was a blacksmith the materials would have to come from somewhere. I doubt they had mine shafts. Do we suppose they stored glass for the occasional broken window or was there a beach nearby? The area they had carved out simply did not appear extensive enough to support a group of that size.
Hmm. Seeing how they promoted the deception that they lived in fear of the creatures in the woods, would they actually dare to chop down the trees required to build their homes?