We have just received twenty TT GO motes. They have an ESP32 MCU, an SX1276 LoRa chip, an OLED screen, and a battery with its charger. And they are quite cheap! So we'll start testing them very soon :)
Some nice websites with information about this board are TTN's Big ESP32 + SX127x topic part 2 and osresearch's esp32-ttgo repository.