In more than 6000 hours on DH8-300 and DH8-400 I have run into a lot of icing conditions some with heavy ice (Propellers throwing ice against the ice shields on the fuselage). Sometimes even level change would not help and we had to stay in these conditions for quite some time.
Never ever had any problems. Not even a noticable speed or climb performance loss during stong ice buildup. The Canadians certainly know how to produce planes who can handle ice.