Ed,

Understood.
I do that as well.
In my otherwise-unused SD card slot I always have a big MicroSD card.
- I use Task scheduler to run a backup script to it every hour.
- It is handy for those times when I've made a mess things [provided I realise within the hour]
- I take it with me when I go out & have an adapter to connect it to my mobile phone so I can open files on that if needs be. This has reduced the number of short trips for which I've felt the need to take a computer with me.
Being permanently connected, it is vulnerable to malware attack.


All the best,
Denis