Nice move. Exactly what I did. Phoned Hyundai about availability for stock Ultimate I5, cancelled the VW order, and 10 mins later vw was off my mobility order and replaced by the Ioniq. You may get the car next week, or a couple of weeks. Depends on how busy the garage is at the moment. My one had to come from another garage which takes time.
But you need the car ASAP, it will be fine.