If you have a license of WHS, which is not bound to any special hardware, you could install that version in a virtual machine and use this as basis to keep the homeserver.com domain registered.
Of course with all the hassles (i.e. patch management, having to disable automatic router configuration by this machine etc.).
And nobody can tell, how long after expired support for the product the domain will still be maintained by Microsoft.
Best greetings from Germany
Olaf