Enable the Legacy Contact on the Apple Account, and the contacts will be able to more easily (but safely) get access to the Apple Account.
To archive your iCloud data:
But… until it’s all been written down somewhere (and you may already have this underway), I’d focus less on the photos and iCloud data as valuable as hose are, and more on the regular payments and regular bills and payment accounts and passwords, social media accounts, taxes and tax info, absolutely focus on birth and marriage and vehicle titles and whatever other certificates as these legal papers can be required for other paperwork, and related data. Any genealogy data, if available. This all might include info on safe deposit boxes, whatever properties including gravesites, debts or royalties or life insurance owed you and your heirs, whatever. Pointers to specific and particularly valuable items too, and valuable for whatever reason, whether financial or sentimental or historical or whatever.
Oh, and where the will itself is located.
An accountant or lawyer can undoubtedly have good suggestions here, too.
As everything else is getting sorted, download the iCloud data somewhere. And yes, a terabyte of iCloud can fit onto 750 GB, but I’d go somewhat bigger just because our own data usually only tends to increase, and you probably want to have two copies (or maybe more) of this data because you can alternate the downloads without having to overwrite what you already have downloaded when re-downloading the latest data.
The data security user tip covers some of the technical and backup and related considerations:
