You divide the daylilies if the clump has gotten so large that the number of blooms diminish. Some daylilies need dividing every few years, some can go longer. You can give the extras away as freebies (give them to your garden club, pot them and put them out on the curbside, whatever - I obviously don't know your living situation up there).
I have an acquaintance in Montana who I am going to give some daylilies to, and I've been searching out info from other people on this forum in similar climates (Canada, for example) so I can make some informed choices for him. What I have learned (thus far) is to choose dormants and maybe some semi-evergreens, and for bloom season choose EE, E, and EM (extra early, early, and early midseason). You can throw some M (midseason) daylilies in there, but if you get an early frost you will lose the buds. (I wouldn't expect rebloom... unless it was a cultivar with "instant" rebloom, such that the rebloom scape is coming up pretty much the same time as the first bloom scape.) Considering that the nights would be cooler, CMOs sound wise, too. (Thus far, among what I have, I only have a few daylilies that I think would be worth him trying, and one of them (the only CMO in the bunch) is too new a plant here (with slow increase) for me to divide it.)
