Mine are about the same size that Maurice has. Mine are still reblooming, but barely. I think I have two rebloom scapes right now. Maybe more that haven't bloomed, but I didn't look that closely. Two years ago there were a massive amount of blooms, and just as many reblooms. It is time for me to take care of the plant and divide it.
I have always divided early in fall/autumn, just as it is starting to cool down some. My feeling is that they get settled in before winter, and I'm not disturbing them in the spring, so that they have a better chance of blooming. I've never lost any doing it this way.