I suspect this thread might be more appropriate for the "Long-Term Preparedness" section. There might be some small chance that it would be a short or mid-range problem but mostly this is a long-term issue.

Short-term the usual hacks should work well enough. Like field expedient materials stuffed into socks or the sleeves from a long-sleeve shirt as makeshift shoes. Depending on the area going bare foot might be an option. Crossing swamp and streams I have been known to doff my boots and ford the wet area barefoot.

Also, assuming you have footwear and clothing, it might surprise people exactly how long you can keep them in service if they are maintained and patched or mended in a timely fashion. During WW2jungle fighters, far from supply lines, made a habit of carefully inspecting their clothes and mending any imperfections as soon as they were spotted. Even with hard use in the rotting jungles some soldiers were able to keep articles of clothing functional for years even as they were patching the patches and the y were more repaired than good cloth.

Also during WW2 German infantry units each had a cobbler. I think it was one per platoon. The soldier had been trained in the trade as a military specialty and issued a cobbler's kit. With regular inspection, dressing, and repair quality leather boots can be patched, resoled and kept in service indefinitely.

The cobbler also worked to maintained the unit's load bearing equipment, tents and tarps and some uniform repairs. The individual soldiers were expected to do the majority of their own maintenance on their uniforms.

In the end it is the standard set of options. You either beg borrow or steal replacements, patch what you have, make do as best you can, or do without.