My experience with spring sickness is not quite the same as Sue's. In general for me the plants that suffer from spring sickness (ss) do not recover well enough to bloom at all normally. One clump did not flower at all this year after suffering ss and the fans are not even now anywhere near normal flowering size. Another clump of a different cultivar managed to produce one very poor short scape that was not anything like normal in height or budcount. The rest of the fans are not normal flowering size; they are very short and not much larger than healthy seedling size even though they have been pushed heavily with fertilizer. A third clump that suffered ss this spring managed at the same time as its fans were being decimated to produce a number of new healthy fans at a short distance from the clump. It has produced a few scapes but not as many as last year and I suspect only from those new fans.
In my experience plants that suffer from ss take more than a year to become the same size and as healthy as they were before the ss. I always consider ss to have both apparent positive and negative aspects. A small clump of a cultivar that suffers ss here will be set back for some time but when it finally recovers will be many more fans than it would have been otherwise. That is true for all three cultivars mentioned above that suffered ss this spring here.