If you have bitcoin in a different wallet, and the wallet is kept in a house, then it’s almost the same thing as keeping all the bitcoin in a wallet. If a house is being affected by any of the disaster that you mentioned above, even if you have more than a wallet in the house, it’s going to be affected. So if you are having bitcoin in different wallets, maybe there is a way in which it’s going to be done so that all the wallets won’t be in a building. But the best thing to do is just to properly secure your private key.