I feel very confident in saying this.
I have lived as a vegetarian (with various transgressions) since I was 11.
I have been in Mexico in the summer, in Switzerland in the winter, in the American South otherwise, and I can say you can find an apple and peanut butter, under even the greatest duress. You can find peanut butter in gas stations, bodegas, in less than savory nicotine-stained
cupboards and in your suitcase, if you’re smart.
I don’t speak Spanish beyond “left,” “right,” “hungry,” “thirsty,” “ocean” and “airport” and I can’t speak a word of French beyond counting to 10 (except for the middle) and butchering “[Please, God,] do you speak English?” But, I try to learn “peanut butter” before going anywhere outside of the country.
A go-to Don’t Starve foodstuff is essential. Best to find yours before your next trip.