Stachyurus yunnanensis is evergreen and so does not suffer from the curse of S. praecox - the late frost.
It seems perfectly hardy but is happier against a wall.
Ribes sanguineum 'Tydeman's White' is a robust currant that will perform anywhere and only needs to be fiercely pruned to keep it in check.
Bergenias get a bad name - but I love them.
B. emeiensis is perfectly hardy and is flowering now. It has neat foliage and delightful white flowers with a hint of pink.