Well, I have just around 1200hrs on both GA and regional turboprops and had just one hairy moment regarding the icing. We were climbing through FL160 (on the nice, warm summer day over the central Europe) and started to pick-up so much ice (and so quickly) that our faithful ATR 42-320 was unable to climb any further. We immediately requested a descend to the lower level, which solved our troubles quickly. But don`t forget the -320 when loaded climbs like the Wellington on the Berlin raid, King Air and other biz-props do much better
So basically the old advice is - change the level (2-3000ft is often enough) and the icing usually stops. And never try to climb above when the performace is not sufficient, it can (and does) lead to the wing fall off (happened to friend of mine many years ago). And if really in troubles , don`t forget that AoA is everything when the wing is contaminated, which basically means the speed up. But again, if able to go lower, do it instead of holding the level with increased speed, it can be matter of time when the ice build-up is so huge that you are in troubles again. Speed increase is only temporary solution.
On the other hand I cannot remeber the situation when we had to stay on the ground with the jets going. Of course I would postpone the departure when the severe icing is reported in the lower levels, but it never happened to me even during the winter.
By the way, contrary to the popular but incorrect myth, the ATR when properly operated can cope with the ice wery efficently and safely. The two-chamber de-icing boots are really good!