This is my actual itinerary. The departing flight from JFK had only 5-8 seats left in the coach cabin when I booked 30 days ago. The departing flight from Acapulco to Houston was the same. I wasn't able to find the seat availability for the other two legs.
Date: March 18 Flight: DL 279
Departs: New York-John F. Kennedy Int'l, NY (JFK) at 10:01AM
Arrives: Mexico City, Mexico (MEX) at 2:24PM
Class of Service: (N) Seat: not assigned
Flight Duration: 5 hours 23 minutes Miles: 2086
Meal Service: Lunch Aircraft: Boeing 757-200
Date: March 18 Flight: AM 307
Departs: Mexico City, Mexico (MEX) at 7:15PM
Arrives: Acapulco-Alvarez Int'l, Mexico (ACA) at 8:05PM
Class of Service: (U) Seat: not assigned
Flight Duration: 50 minutes Miles: 191
Meal Service: Brunch Aircraft: M80
Date: March 24 Flight: CO 885
Departs: Acapulco-Alvarez Int'l, Mexico (ACA) at 3:10PM
Arrives: Houston-George Bush Intercontinental, TX (IAH) at 5:44PM
Class of Service: (G) Seat: 11-A
Flight Duration: 2 hours 34 minutes Miles: 945
Meal Service: None Aircraft: 739
Date: March 24 Flight: CO 1638
Departs: Houston-George Bush Intercontinental, TX (IAH) at 8:40PM
Arrives: New York-La Guardia, NY (LGA) at 12:49AM on March 25
Class of Service: (G) Seat: 14-F
Flight Duration: 3 hours 9 minutes Miles: 1415
Meal Service: Snack Aircraft: 735