Exactly what you are worrying about happened to me. Cycling along, not particularily fast, minding my own business. Whack!
3 door BMW convertable with the biggest doors know to man ‘kicked’ open (i.e. he used his foot to opne it as its so blimmin massive and heavy you cant use your arm when the car is leaning towards the gutter). No time to react. Wheel in to door, me through the window (no frame as was convertible), me on the floor surrounded by glass, door bent back to the wing, lots of glass embeded in my face and hands.
No lasting damage, but am now petrified of parked cars. I check every parked car through the window to see if anyone is in it, or look in the wing mirror to see if there is anyone there. If that doesnt work, I slow right down.
Riding the distance of a BMW car door away from a parked car is not practicle. I would have oncoming cars in my face, they are that wide.