Based on this article: Tor Entry Guards - Whonix
Is it advised or beneficial to use a different Whonix-Gateway (or device) when changing locations/residences/countries (e.g. one separate Whonix-Gateway for each location) to reduce the risk of Tor Entry Guard Fingerprinting?
Possibly, but you also increase the chances of using a malicious Tor guard relay with a different circuit.
Is it possible to derive a practical advise?
As the risk of using a malicious Tor Entry Guard does always persist I would assume you should use a separate Whonix-Gateway when moving around. I mean it could be the case you are already using a malicious Tor Entry Guard and fix this by changing the Whonix-Gateway.
If you are concerned about Tor Entry Guard Fingerprinting, use multiple separate devices, each with a different Whonix-Gateway, so that each geographical identity/persona is easier to manage and maintain.