this is an extremely long walk. like 3-4 miles (the signs say this). but at least there's country music blaring, iah is fun for a dingy airport
maybe just try to get your cart on, it's houston errybody breaks rules there and nobody snitches
maybe just take an uber from terminal to terminal? also arrivals E (all arrivals) have free baggage carts, does anyone know if departures D is the same?