You will just make it difficult if you will divide it into multiple wallets. Securing each of those properly would take a lot of time and effort. Putting it in a single address or wallet is enough, just make sure to save the passphrase and create multiple copies on where you think it is safe. Never share that info with anyone even if they are your relative. If you are scared that something might happen to you then look for someone that you really trust and will inherit that amount of bitcoin. It may be not that big amount now but in the future, it will greatly benefit the next generations.