Many programs make use of temporary files.
If the temporary file can not be created that program will fail.
If there is no spare SD card space then temporary files can not be created there and so programs which need temporary files will fail.
The solution is to create more space by deleting unneeded files from the SD card.
An interesting solution would be: download Knoppix (or any of many other linux live-CD distributions), burn it to CD or DVD (or use any of various tools to write it to USB or flash media), boot from it, and then use that to copy from the one SD, and then to create comparable filesystems on the other SD.
This is NOT possible on Windows but it can be done on the Pi itself using the SD Card Copier included in Raspbian.
Backup image of SD Card describes how to produce a small installable image from a running Pi.
This runs on the Pi, but the can produce an image on a Windows (or any other) computer - I do this to my Mac.
This initially is a little involved to ...
If you want to recover a broken SD Card the operating system must have access to the device. You must have at least a device file, something like /dev/sdb. Because it is broken it's possible that you don't see partitions (/dev/sdb1) but you need the raw device file to access the SD Card. But as shown with lsblk the operating system cannot find the device so ...
It does sound like the SD card reader has gone pop.
Format a spare card (less than 32Gb) using another Mac / PC as Fat (one partition)
Create a small text file on this card using any editor - call it test.txt to check it accepts files OK
Put this card in the on-board SD Card slot
Install Raspberry Pi OS Lite on another card
Put this card into the ...
The issue is not normally the destruction of the card (I've used normal ones in -16C) but the actually data or OS file system being corrupted by not being written to the card as the machine dies due to the environment.
I used to handle over 70 different bits of kit in the field that where mission critical and had to handle temperatures of +40C down to -35C (...
This is more of a "workflow" answer as I'm unsure exactly what environment you're working in. If you have specific questions, you may either edit your original question, or use the Comments (sparingly please).
Duplicating your system as an image file:
You can use image-utils to create an image file of your "existing unit". One of the ...
USB 2.0 has a maximum bandwidth of 480Mb/s, or 60MB/s although speeds closer to 30MB/s are common. The raspberry pi foundation says that any SD card will work and give examples of cards that operate at 4 and 10 MB/s so a USB 2.0 SSD should have sufficient speed.
The Pi3A was released on 15 Nov 2018.
Any OS older than this won't work, although you COULD try updating kernel and firmware from a later release.
NOTE DO NOT use rpi-update (at least without selecting a Stretch compatible release - which is not quite straightforward).
Running sudo apt-get update; sudo apt-get install --reinstall raspberrypi-bootloader ...
It seems the cloned SD Card boots up and is running but has problems at least with the network interfaces. On a cloned program it also has exactly the same system parameter like hostname, MAC address, ssh server keys, UUID and PARTUID of the storage and maybe other parameter I just don't remember now. This is no problem if the clones are running on different ...
You can clone SD Cards.
There are a few things to watch, depending on whether they are to be used on the same network.
However DON'T use Windows!
The Pi has a SD Copy program, and you will find hundreds of similar questions on this site.
I assume you can only read the fat32 boot partition when configuring the SD-Card in a card reader attached to another non Unix computer (MS Windows, Apple Mac) before booting it in the RasPi. The hostname is defined on the ext4 root partition in the file /etc/hostname containing the name. On the running Raspberry Pi you can just create this file in the boot ...