At home: Put cut vegetables in a large resealable plastic bag. Keep, chilled, up to 2 days.
At home: Combine oil, vinegar, lime juice, minced cilantro, salt, pepper, sugar, chili powder, and chile flakes in a small resealable plastic bag or container. Keep, chilled, up to 2 days.
At campsite: Add dressing to vegetables, shake to combine well, and let sit 15 minutes, stirring 2 or 3 times. Serve garnished with cilantro, if you like.
Note: Nutritional analysis is per serving.