climbing hydrangeas and pyracantha would grow in such conditions

I've also read that Morello cherries will flourish against a north facing wall they look lovely trained as a fan. And you can eat them to boot! I'm intending to plant one this coming year. Obviously things like hellebores, mexican orange blossom, hostas and camellias work in the shade too, but they don't climb. However, you could create "shelves" on the walls (or freestanding) and arrange pots on them? I don't know how 'ornamental' you want to go. Ivy will hang down from pots/baskets hung on the wall.

Alcina

Schizophragma hydrangeoides does well I believe, also hydrangea petiolaris and wisteria flower profusely on my and my neighbours north walls. All will fill that space, and more, in time. As will most ivy. Golden hop is usually recommended for a south wall, but I find mine gets scorched when it is too hot and dry, so might be worth trying, if you want annual growth.

Brian

Garrya elliptica and climbing rose Mme Gregoire Staechelin do well against a north wall. There are also honeysuckles and many varieties of clematis.

Parthenocissus henryana is an lovely, deciduous, woody, self-clinging climber that does well on north walls. The leaves are veined with silver, which really brightens up a dull area, and they have purple undersides. It also has good autumn colour.