We want to upgrade Linux Mint 18.2 to version 20, and we don’t want to go through 3 upgrades to get it done. Instead we will make a proper inventory of the current system, back up all the stuff we want to keep and install Mint 20 from scratch. This approach should work fine for all Debian based systems.

If you want the possibility to get back to your previous system, make sure to make a full backup and keep it safe somewhere, but in most cases it’s best to move to current affairs and deal with possible trouble by fixing the issues in the new system.