Is it possible to have the Enyaq display a more normal display of car mileage, something like total mileage, miles since last trip reset, miles this journey etc

Yes - on the Infotainment screen. Pin the 3x2 or 2x2 Driving Data panel. If you don't know how to edit the Infotainment screen, you can find details on the Skoda video manual website: https://www.skoda-auto.com/services/enyaq-videos