I had a hunch your reported zone was due to micro-climate issues. You could be either 7b or 8a.
HMF says Mermaid is hardy to 7b, so you could take a chance on that rose.
Albéric Barbier or almost any hybrid wichurana they have the cold hardiness you need.
Baltimore Belle, Veilchenblau, Étoile de Hollande, Cl., Félicité et Perpétue, Iceberg, Cl., Paul's Lemon Pillar, Long John Silver.
No, I haven't grown these roses, but have only read about them.
Good luck. I know I would have a hard time choosing.
btw .. you might be able to grow stone fruit trees in your canyon.
