I've not grown any of Emmerich's myself, but I understand that they are hardy.
Richard Norris, Curt Hanson, Steve Moldovan --- they are all names associated with really hardy daylilies that perform well with lots of blooms in the north. And, many of their plants go for under $30. There are a lot more hybridizers that work for northern hardiness, those are just 3 that come to mind.
