I'm not understanding your ideas. You're talking about cucumbers in an area that only gets a few hours of pm sun? I always thought they needed full sun.

Anyway, yes, a climbing hydrangea might work. Any of the ivies too --- English, Boston. I have a lot of Virginia Creeper in my yard too that started as volunteers. They will all grow in low shade, very well.

Maybe try one of the native understory vines:
Cross-vine (Bignonia capreolata)
American Bittersweet (Celastrus scandens)
Leather Flower (Clematis versicolor)
Passion flower (Passiflora incarnata)
Yellow Passion flower (Passiflora lutea)
Wooly Dutchman's Pipe Vine (Aristolochia tomentosa)

Many of these are larval food for butterflies (caterpillars) so you might end up with more butterflies too.

I'd stay away from any ivies, we're still battling the ones planted by a former houseowner. That and the euonymous-- horrid vines, very persistent and they root everywhere.

Humming Bird Vine, Clamatis, or Honeysuckle. Toni

I've got a couple honeysuckle vines growing in the same situation. They're doing pretty good - they bloom very good - but I get alot of die-back to prune off each spring, I assume from them having northwest exposure. But it's okay cuz they grow so much it keeps them in bounds.

I have a variegated porceline berry vine that is three years old and gorgeous! The green and white leaves create interest until the tiny white flowers turn to blue/purple berries in the fall. It is so lush. I have one on either side of my wooden arbor where it gets about 4 hours of sun a day and it thrives. It has gone up and over the arbor in a thick mass and creates shade under the arbor. I never cut it as it blooms on the old wood. The two vines together cost me $32 and it was some of the best money I ever spent for garden plants. Everytime someone goes up the sidewalk into the back yard they ask "what is that interesting vine"? You might want to go to "Google Images" and take a look at it.
Tina