Ofc how they perform in reality vs their published specs no one knows.
In the past at least likes of China and Russia tended to inflate the specs that they made public whilst the west tended to keep the real figures hidden and release far more conservative figures especially when it came to things like maximum speed, range and operational ceiling.
Also there is the Arctic you can take off and land on ice and use either an icebreaker or a sub for deployment and recovery.
China does have some advanced drones with a substantial range e.g. https://en.m.wikipedia.org/wiki/Guizhou_WZ-7_Soaring_Dragon
Ofc how they perform in reality vs their published specs no one knows.
In the past at least likes of China and Russia tended to inflate the specs that they made public whilst the west tended to keep the real figures hidden and release far more conservative figures especially when it came to things like maximum speed, range and operational ceiling.