What a great opportunity! A few questions to narrow down the possibilities:

color - not just the color, but the brightness vs softness, etc
once blooming or repeating?
type of bloom (large HT type, old fashioned tea type (which might look great nodding down from above), clusters of tiny flowers, single small flowers, etc.
Jackie

Bright I think. It's at a distance so the showier the better. Once blooming would be o.k. if the bloom went on for at least a month. I prefer repeat bloom though. Type of bloom - I guess I don't care. Again, whatever would be showiest from a distance (against a background of green green green).
Thanks!

If you want a monster plant that grows like a weed, try YELLOW BLAZE aka CLIMBING SUN FLARE. It gets smothered in gorgeous bright yellow blooms for several weeks in the first flush. It gets an occasional lighter flush later in the season.

Sombreuil fills the bill. It's giant, healthy, and gorgeous. I am sure there are others. Maybe you can say what color you prefer, because there are others including Cecile Brunner, and New Dawn. I grow Madame Alfred Carriere and while she is very large and beautiful she does have some problems with disease.

There is a new climbing rose called Purple Splash that might work. Look it up in HMF to find pictures. The only thing is, I haven't heard about its disease resistance - perhaps someone else here has that info.

Jackie

Here are some bright ones I like but I don't know how they'd be for disease where you live:

Parade vigorous, brilliant pink, beautiful form, great repeat see pics on HMF

Freisinger Morgenrote aka SUnrise brilliant orange and pink, good repeat, not sure of eventual size

Fields of the Wood beautiful red, repeats, good health

Dublin Bay "

Rosarium Uetersen
Westerland
Autumn Sunset
Crepuscule a pretty strong apricot, great health, repeats, gets large

Some of the Austins can be grown as climbers.

I have Purple Splash Jacqueline & it is very healthy. It's growth pattern is similar to 4th of July. However for this particular spot I'm talking about I'm thinking of a monster climber. Not white or cream. Beth mentions Climbing Sun Flare & I'm going to look into that one. I think yellow or orange or red will show best from a distance. I'm also wondering about everblooming climbing Cecil Brunner if anyone has experience with that one.

Laguna is also quite disease resistant. Many thorns though. Not the most refined rose, but certainly should be vigorous. Not sure how it would react to damper weather than here.

I have everblooming Cl. Cecile Brunner, and she was already starting to bloom, just a couple flowers though, a few weeks ago after taking a breather for the winter cold. Now getting LOTS of buds!. I've never sprayed any rose, so roses in my yard have to be able to do well without needing to be sprayed, and CCB always looks great, covered in leaves, and when she blooms--she can stop traffic with the blanket of pink! But I'm in an inland hot area, not as cool as your area, so I can't speak to the difference. This plant is around 40 years old and is MASSIVE!!! She has a trunk like a tree. She grows over everything in her path--goes up the tall juniper on her own, and cascades out of it, which is quite a beautiful sight. Will swallow any roses nearby if given a chance. Gets trimmed too, which she doesn't seem to mind, just grows back.;) Mine can handle once a week watering, even in the heat of the summer, but her roots are very well established and protected with mulch/groundcover and the shade that she provides them.

Rose 'Linda Campbell' perhaps. We love ours.

Kate

Here is a link that might be useful: Linda Campbell