Bootable ISO Backups: Best backup solution for encrypted, bootable ISO Disk Images, with partition autoshrinking?

I am running Ubuntu Server 22.04 (amd64) on an intel machine with Full Disk Encryption. It is a server, and therefore I can't risk it not surviving any corruption, data loss, or cyberattacks. Therefore I am looking for a backup solution that can create daily bootable disk images of the running server, and save them to an external hard drive. In case of corruption, I ideally would be able unplug the external hard drive with .img or .iso backups, plug it into another computer, and flash the corrupted drive with the bootable image backup. Then I could just plug in the flashed drive back into my PC, and run a completely intact OS.

On top of that, I would like for it to be compatible with Full Disk Encryption with LVM, and be able to encrypt the .img backups with FDE as well. Lastly, I want it to also shrink the partitions of the .img files the smallest size so that there is no unused free space in each partition. That way, each backup bootable .img file will only be say, 10GB, instead of 128GB. When the .img file is then reflashed to another drive (using say, balena etcher), the newly flashed drive will automatically expand its shrunken partitions to the full size of the drive when Ubuntu gets booted.

There is a series of scripts that a guy on the Raspberry Pi forums, that do exactly what I am looking for. The backup solution I require is almost identical to these image file utilities scripts for the Raspberry Pi. The only exception is that the Raspberry Pi utils don't support fully encrypted disks, and dont offer encryption for the final .img files it produces. Feel free to take a look at the pi scripts here if you need a better Idea of what I want.

In summary, I need a backup solution for Ubuntu Server 22.04 (amd64) that can do the following things:

1. Make bootable disk images in .img or .iso format of a Running Live Ubuntu Server, and save them to an external drive.
2. Can run on an Ubuntu System that has full disk encryption enabled
3. Can encrypt or password protect the resulting backup .img or .iso files
4. Can shrink partitions (or at least the root partition) to smallest size possible in each backup .iso or .img file, so that each backup file is much smaller than the running system.
5. Can automatically expand shrunken partitions (or at least the root partition) upon booting a newly flashed Hard drive.