I've had it 3 times, twice on the left shoulder, once on the right, each time it has taken around 18 months to heal, I do have the vast majority of my range of movement in both shoulders, but I did loose a lot of muscle, which hasn't come back from normal use. I did have physio for a while but I was told it was more for when things get better to maximise movement, not whilt the shoulder was frozen. the exercise was to place my forearm against a wall and apply pressure,
I don't know if it helped but the fact i can lift both arms above my head with ease, i will do the exercises again should it re-occur.