There's reason why they extended it (Enhanced Extended Range). It was only technical limit due TDMA timing advance. It had nothing to do with the actual signal

There's reason why they extended it (Enhanced Extended Range). It was only technical limit due TDMA timing advance. It had nothing to do with the actual signal reception strength / transmission power required. So in 800 MHz range 120 kilometers should be well achievable with 2 W transmitter. "GSM has a fixed maximum cell site range of 120 km, which is imposed by technical limitations. This is expanded from the old limit of 35 km."