Some of the best irises I grow are in the SDB/MDB classes. Here are a some that I like which seem to "love" the cold winters here.
Our current temp as I post: (6F, -14C)
This one is a tiny, tiny MDB; Alpine Lake from A. & D. Willott, 1981. Its growth is almost unreal!
This batch is out in the veggie garden.
This is Bedford Lilac from Bennett Jones, R1991. It takes a lot of cold & winter abuse.
And this is likely my all-time favorite in the SDB's: Bluebeard's Ghost; Sensational in every way!~
By Paul Black R2006 (exceptional iris)
It looks like I am stuck inside for most of the day. My outdoor chores are mostly done.
This thread helps me remember that spring will certainly come again!