You can't be serious... you have to plant up a bank a mile long? You'll need help...

Some of the cotoneaster and vinca varieties would be worth a look, maybe different ivies all mixed together to give a pattern of colours and textures.

Will you see it from the house? Does it need to be pretty?
Can you water it or is it fending for itself?

Prostrate junipers cover a wide area eventually but it takes a long time so you'd need something else in between until they got going. Some areas of ericas would look nice with the daffs. Theres a prostrate cotoneaster too that gets quite wide and there's a prostrate ceanothus*thats evergreen as Teadrinker says. . Could you grass it for starters and plant it up by degrees - would make it a less daunting task. *
Just looked on goypedia and found this advice from Bamboo:
*"Cotoneaster dammeri, or Cotoneaster Queen of Carpets - both only get less than 4 inches high, and Queen of Carpets spreads and spreads. Evergreen,tiny white flowers followed by red berries in winter, no pruning"
(Hope you don't mind Miriam)