My 20.3 version of Mint is now telling me that I have 50 days until it is no longer supported.
I believe I can't update my 20.3 version to the 22.1, long term version, directly.
I would need to do a fresh install of 22.1, which I rather not do, or do an upgrade to version 21 and then, upgrade to version 22.1, which is also a long term version.
I have just done an image of the computer hard drive so I am good, if anything goes wrong during the upgrades.
It looks like you're right. Upgrade to 21 and then 22. Did this page provide you with that info?
https://forums.linuxmint.com/viewtopic.php?t=432084
A fresh install of 22 would be much easier if you could back up your home drive, more so if you have a separate partition/drive for /home. Make sure to backup your hidden dotfiles (they begin with a dot like .bash, for example, if you want to restore program settings and desktop configuration (the "look").
But if you want to go the double upgrade route, you might also consider using Timeshift. Do it once, then upgrade to 21, do one again if everything looks okay, and then go to 22. If something goes wrong, a previous release can probably be restored faster than an image because, after the initial run, it only keeps track of changes. By default, it doesn't backup data, though, so make sure you configure it to do that first.
If you do a fresh install, you could put /home on its own partition for future upgrades, if you haven't already. I still back up my personal files daily anyway, but that's me.
Good luck!
Steps for the upgrades are on the site somewhere. I always found then straight forward. And if you have a separate /home, you can do a fresh install and not format /home. Quick.
But the upgrades seemed fairly easy. And interesting. Do the 2 upgrades over a period of time.
You do have an image to fall back on.
Marilyn's computer has gone thru many of these.