Randomly thinking that I should maybe update the satnav before a planned journey as you do, I installed the Garmin Express satnav software onto my PC and started the update process.
(For a 2018 Sport Navi.)
It's quite easy I have to say, though the Garmin site is slow downloading at only 8Mbs here so it seemed to take ages to download the approx. 7.5 Gb file.
2020 version though it said, and it took only about 20 minutes to install into the car from the USB port.