Patrik,
All aircraft are sensitive to icing. Cessna produced pilot notices several years ago addressing the need to maintain speed and restrict flap use in ice; these cautions applly to all high wing Cessna's, particularly the 200 series airplanes.
Avoiding ice is always the right choice. A number of accidents have occured when Caravans flew into icing conditions, but then accidents have occured in many aircraft types due to ice.
The nature of ice is that it can be highly unpredictable. I've been in ice when the aircraft ahead was reporting no ice, the aircraft behind was reporting no ice, and I had severe icing. In that particular case, it was very localized due to orographic, or terrain-induced lifting. However, I've done a certain amount of icing research in flight, including carrying some sophisticated sensor equipment aloft to measure ice crystals and water droplets as part of atmospheric testing. I've seen icing be virtually non-existant one moment, then blossom into a rapidly building situation the next. Remember that the definition of severe icing is any time icing exceeds the ability of the aircraft systems to control and remove it...what's mild ice to one airplane can become severe to another.
If an airplane is iced and can't remove it, then the best that can be hoped for is that the aircraft will continue to fly safely with the amount of ice it's carrying. That's the best that can be hoped for. It only gets worse from there, and if the aircraft isn't doing well presently, any more ice will only make things worse.
Tailplane stalls have been thought to be applicable to T-tail airplanes, but other aircraft are fully susceptible, and the Caravan is certainly among them. the horizontal stabilizer is thinner than the wing, builds ice more easily, and can stall, resulting in nose own pitching moments...requiring pilot actions opposite to what one might normally take in a conventional stall condition. These pilot actions include decreasing engine power, unconventional flap practices (raising or leaving alone, if the stall occured when flaps were applied), and applying aft elevator to increase elevator download. When the stall occurs and download is lost, the pilot may be unable to prevent the aircraft from pitching nose down. If this occurs close to the ground, recovery may not be possible.
This applies to many aircraft other than the Caravan, of course, but the caravan has seldom been thought of as a tailplane stalling airplane, when in fact it is.
An important aspect of ice to consider is that while the airplane can carry a very heavy load of icing, it's not particularly tolerant of the changes in aerodynamics; particularly disruption of the airflow layer over the top of the wing, and changes in the angle of the downflow at the back of the wing.
I've hung out of Caravans on many occasions while skydiving, often with a whole group of people standing on the side of the airplane, hanging off, prior to letting go for the skydive, and the airplane is tolerant to a point. I've also flown them and run out of control when enough people are hanging on outside the airplane, horsing around.
Even a small layer of frost on the wing is enough to seriously disrupt lift, causing early boundary separation on top of the wing, and resulting in significant performance loss.