One thing that has not been mentioned is that some daylilies naturally make smaller fans than others. I have a daylily called Something Angelic that makes VERY small fans and has a small bloom. I recently sold some of it and told the buyer what to expect. I sent mature fans with great root systems but the fans were short and small. They simply don't get bigger here.
My garden is in TN, zone 6 and we don't get snow cover in the winter. The evergreens and semi evergreens grow, then get killed back by a hard freeze, then put out new foliage and then it gets killed back. This happens over and over during the winter and by spring, the plants have use up much of their stored energy and the fans are much smaller in the spring than they were in the fall. It takes a while for them to regain. normal size. Pat Stamile posted about this very thing recently on the Robin. In the deep south, the daylilies can continue ue to grow all winter without getting killed back, so their fans are huge when shipped.