Understanding the network functioning

Using LoRa to communicate with your drone should be fine as long as your drone remains available from gateways that has caught the uplink message. If you don't care about the downlink part and you won't communicate back to your drone, then there's no issue at all and your node can move as it wants.
However, if you need an answer from the network, then, in the worst case, you'll need to be reachable by all gateways which picked up the signal for at least 2 seconds after the uplink has been sent. Because of the limitations regarding the gateway band usage, you cannot really know a priori which one will be used to send back the response.