Heat oven to 400°F. Toss tortilla strips with 1 tablespoon oil and 1/4 teaspoon salt on baking sheet. Bake 8 to 10 minutes, stirring once, until crisp.
Heat remaining oil in soup pot; cook onion 5 minutes. Add garlic, chipotle, and cumin 30 seconds, then tomatoes and 1 cup broth; simmer 5 minutes.
Immersion-blend tomato mixture smooth. Add remaining broth, chicken, and remaining salt.
Gently simmer 18 to 22 minutes until chicken 165°F. Remove, shred, and return chicken.
Add lime juice; divide among bowls. Top with measured baked strips just before eating.