How to get the Gwent cards if you missed them in the tutorial
According to this comment on Reddit, the cards are available from the Shopkeeper you rescue from the Griffon during the tutorial, as of patch v1.04.
Having checked, it seems that that shopkeeper now has the four cards that I'd missed - namely:
- Catapult
- Blue Stripes Commando
- Crinfrid Reavers Dragon Hunter
- Foltest (Lord Commander of the North)
After being rescued, the shopkeeper is located to the west of Woesong Bridge, in White Orchard.