-snip-
As an addendum to this, if you are planning to encrypt your seed/private key/wallet before uploading it to your email or cloud storage, you should do so on a clean, live OS on an airgapped machine. Much like creating a paper wallet, it doesn't matter how secure the final product is if it was created in an insecure way. Obviously you will need to have your seed or private key in plain text on your computer prior to encrypting it. If you have malware, keyloggers, screen captures, or something else malicious on the computer you are using, it could very well steal your details prior to them being encrypted. Encrypt it on a clean, airgapped machine, transfer to a live machine via clean removable media, and upload to the cloud.
However I also wouldn't recommend this. Offline backups are safer.
But even if you think of doing so, you should first secure your email with strong password and 2fa.
2FA on all your accounts is a good idea, but it should not be relied on. Depending on the type of 2FA you use, it is possible for an attacker to transfer or clone your 2FA method to a device they own, and it is also possible to disable it altogether.