I back up to the Internet but that is an extra cost and I guess if you were unlucky enough to be hit by any of the disasters you have listed 3D art will not be your highest priority. My as I would miss my art I think I would miss my photos more, particularly family ones. As you say, let's hope nothing this ever happens.I try hard to remember to back up all my new work as I do it, otherwise any disk failure will make me cry...lol.
I have a 2 tb external that I need to clean all duplicate files from amd clean up a bit and then I'll have about another 1.5 tb to use.
That way I can be fairly sure I do not lose my files to disaster, unless a tornado, flood or fire, and I hope that never happens.