I'm very impressed with low power usage from 8Devices Rambutan dev board which together with Huawei HUWAEI E3372H LTE modem uses around 350mA at 5V - that is only 1.75W which is very impressive!
Without LTE modem routes uses only 200 mA at 5V which is only 1W of power, again very low power.
This device is dual band but single radio, so you can choose to run 2.4 or 5.8 Ghz band, but not both at the same time.