I'm trying to dig out the photos but not having much luck right now.
During the certifying test flight of the Ejets. They had false leading edges fitted to the stab. Rather than 2x4 as someone said earlier. These were replicas of the shape and size of ice build up as created in wind tunnel tests. The only difference between the fake ice leading edges and real ice build up is that the fake couldn't be shed whereas in reality such large build ups would partially or fully shed with changing airflows.
Before seeing the picture I would never have believed the stab could operate with what amounted to a 2 to 3 inch extension of oddly shaped "ice". But in fact the aircraft flew to all corners of the envelope.
Of course we do have the Stall protection Ice speed system which increases Vsr by about 5% after flight in icing conditions but I'm told this is as much to do with wing and fuselage ice as it is the stab.
If you have access to the Embraer cold weather ops video you can see the fake ice stab leading edges on the test aircraft. Also note how much Ice they get to build up on the inboard slat which isn't anti-iced.