I think Linux Mint 20 support ends in April. Are you going to use the Mint upgrade tool or do a fresh install to Mint 21 or 22? Which backup application are you going to use before upgrading?
I’ve been on 21 for some time now and I just used the Linux upgrade to do it.
Can you recommend a backup application? They all seem hard for me to understand. I have tried to use Backup that came with Mint 20 recently but have not done a restore to see if it works. It uses a compressed format and I think I would rather have a human readable format for the backup files.
I just put docs and my money app on a USB and ran the update. If it blew up I was just going to wipe the PC and install fresh.
First of all, I would not sweat too much about “out of support” stuff. A while back we were using Ubuntu and the project moved to Gnome 3 desktop which was made to act like windoze 8 I think. All things different and there was no way. Primary user was late wife and she was impossible. Besides, if I could not figure it out there was no way I was going to try to teach it. We stayed on that version a couple of years past its support date, when we found Linux Mint.
The updates are usually not bad you just have to go figure out what to do, like get mintupgrade. Now I have a little used ASUS zenbook that was on LM 21.3, and 6 months past updating it and the windoze 11. Spent maybe an hour going to LM22 and then to LM22.1. Then turned micro$oft loose and it was hours and hours! I should just zap the windoze.
For backing up, I use rsync(1) to copy stuff to removable media or another system. One could also make a tar ball and compress it or not. Always lots of ways to get something done.