There is a misconception surrounding heat pumps. Actually it can both heat or cool the car hence has a positive impact on range regardless of the weather. If you do very long trips often then you will appreciate the potential 10% extra range. If you do short trips only then you will see less gains however if you are sitting in a traffic jam on M25 for 3 hours then you will notice the difference.
Enyaq and ID.4 are very similar however Enyaq is more aerodynamic hence has longer range. I think Skoda has better interior in terms of quality and design. The updated model looks stunning.
Ioniq has more advanced EV drivetrain (800v battery, faster charging) and infotainment.