From what I recall, if you prove that your Mac died, you can transfer your license to another one.
I suppose you can always use AROS. It ain't MorphOS, but it is coming along, slowly but surely. It's certainly fun to tinker with that's something I'm coming to find. It ain't perfect, but then again it is free.
If you want something that is rock solid, well then show a little love back to the Amiga community and register this puppy and give it a roll on a Mac, they don't cost much. I mean it's only 300 or less total for a cheap Amiga (MorphOS included), what more could we ask for?
As for hardware dying...
...who's going to replace your classic Amiga when it dies? It's the name of the game in the Amiga scene, we're not dominated by corporate domination. We're Corporation free here my friend, only small time businesses at most, other than that a small community of users who do what they can in their own way to keep the dream alive.