In my experience, The EC 135 will hover 90 degrees out of wind up to 35Kts. with little problem. At 35-40 Kts., you wil sometimes reach full pedal with a proportionate reduction in control. At 40-45 kts., control may be lost and you need to quickly dive on speed to regain yaw control. Above 45 kts. it becomes almost impossible to retain control, especially if ther is any gusting.
This can be a bit hairy , so I would recommend plenty of height [ i.e. greater than 800'] if you need to do it. The a/c may yaw through ~130 degrees with you as a passenger
