I can recommend using Filement(filement.com) for that. It would be a sync interface with you and your data. While as you can add and manage your devices, you ca

I can recommend using Filement(filement.com) for that. It would be a sync interface with you and your data. While as you can add and manage your devices, you can also add your cloud accounts so you can move your backups around and intensify diversification. That said, 50 yrs is a huge amount of time in tech and guarantee is hardly to be held against any business venture or even protocol. But since you have not specified a requirement for automated, non-assisted backups over the time course, i believe that process will be organic and your data will find its way to the future hopefully intact.