If other EVs are anything to go by, adding an AWD system typically reduces range by around 10%, so would expect the AWD MG4 with the 61kWh battery to have a stated range of around 250 miles, but we know that things like spoilers can make a difference and that real range is a function of weather, actual speed and driving style.
One would hope that MG take the opportunity to fix or improve upon some of the less liked 'features' of the current model when the AWD is released. That might include, better seats, the addition of paddles or physical buttons to control drive mode and regen level, and perhaps better quality trim to replace the 'piano black' and more scratchy plastics.