Probably not going to get a Nobel for this

Back when I did my St. John First Aid course, the instructor told us "if you don't have the right equipment, don't be afraid to improvise".

...so it turns out, gas stations don't sell useful-sized ice packs per se, but they DO sell frozen pre-mixed margarita packs that are just the thing for a frozen ankle when applied externally: freezy-cold, but because of the alcohol content, smooshy enough to fit nicely around said ankle.

(Rey twisted her non-driving ankle coming out of the aforementioned gas station. Should be okay with a bit of strapping and a few days to heal.)