Will I have internet coverage on the roads between cities (e.g., Baghdad to Karbala)?

 You must set expectations. You will have reliable 4G/LTE coverage in all major city centers (Baghdad, Erbil, Karbala, Basra). However, on the highways between cities, the signal will be intermittent or drop to 3G. It is essential for navigation but not for continuous streaming. It is much more reliable than Wi-Fi, which is rare outside hotels.