I have friends in northern Wisconsin (zone 3) who grow these successfully. Where they are problematic is areas like California where the temps don't go low enough.

I think that it is true that the issue is more how far south because most bulbs require a period of chilling. I know I failed at growing daffodils in containers that I stuck in what I hoped would be a warm corner and surrounded with leaves so there are limits. Now I bury the containers and dig them up in the spring. The urge to garden is so strong at that point that I dont mind the effort of prying them out of the still frozen ground.

If you get a good bulb catalog, it will tell you the hardiness of bulbs that you're buying (Brent and Becky's or Mcclure and Zimmerman are a couple that I know do.) Most kinds of daffs (tho not all) are hardy here, as are most tulips, grape hyacinths, Colchicum, most crocuses (both fall and spring blooming,) Scilla, snow drops, Camassia, and one kind of Lycoris (squamigeria or something similar) with pink flowers called "Naked Ladies" for their pink blooms that come up in August long after their leaves have disappeared. I've grown all listed here and had them come back for many years so I can attest to their hardiness. The lowest temperature that i've noticed in the years I've been gardening here is -22 F, but we usually have good snow cover.

A few that I know aren't hardy here (that are sold in catalogues like Brecks which in my memory doesn't give accurate hardiness info) include most Oxalis, and the hybrid Decaen large flowered anemones.