For science, I sacrificed some RR. My experience with the new penalties is:

4x 0 RR, 3min cooldown

3x -3RR, 3 min cooldown

3x -6RR, 5min cooldown

3x -10 RR, 10 min cooldown

3x -15 RR, 15min cooldown

after that always

-20RR, 30 min cooldown

MMR doesnt change obviously. I dodged continuosly. Playing games (or probably just waiting a certain amount of time) between dodges will reduce the penalty. Most people probably wont go above the -6RR mark.