You need to drive from Londolozi to Newington Gate at game drive speed; from there south along local roads to the R536; then west to Hazyview; turn south on the R538 or R538 to White River; and finally the R538 to KMI.

That's about 115 km on at times very dodgy roads from the gate, so excluding the first bit in Sabi Sand.

2 hours sounds about right to me.

Johan