It is not easy to help from a distance. The only option is to install existing or additional repeaters closer to the sensor. However, there is still no guarantee that it will work.
At your own risk, you can also add an external antenna to an Aeotec repeater, which also increases the range:
The question is if it’s worth all the effort, or if it might be worth buying an additional WiFi hub from Ecowitt which isn’t bigger than a 5 V USB power supply.
