Don't do that.lots of gorges and canyons and I would like to fly over to get some video.
Agreed! But sometimes you just can't stop yourself to try, right. You can't just leave that beautiful view alone, so just prepare yourself for the risks.Don't do that.
Tello has only a small range about 100m. Except you take a Wifi range extender. But that would not be enough for your intention.
Also VPS will fail. That works only up to 30m.
And the Tello has a maximum speed of 30 km/h. That meens, if you have a wind with a speed of 30 km/h you only can try to hover. No chance to fly, e.g. to come home. And when the wind speed is above 30 km/h the Tello follows the wind. And you will lose her. In the canyons you often have a strong wind.