I keep meaning to try -- as a workable in-a-pinch patch -- high-temperature aluminum foil tape ( here). Might even work to apply to bottom of improvised container before cooking use to protect/reinforce against puncture. A one-foot length, wrapped around a soda straw, would weigh next to nothing and take little room in a kit.

According to data sheet, flame resistant and performance range "to over 600°F." Uses clear silicone adhesive. I wouldn't want to have a meal of the adhesive, but seems like the miniscule amount that might be released through pinhole or small tear repair in improvised foil cooking container could be tolerated, particularly in an emergency situation.

The data sheet does say that "adhesive does gradually thermoset in high temperatures [and] as it thermosets the adhesive mass becomes firm ... but will continue to hold the tape in place."

I'm no chemist or engineer. Wonder if this means even less would migrate into improvised foil cooking container?

Edit: Just noticed price/quantity on link I provided. Here's more reasonable source.