I reckon the first MAINSTREAM and successful remix was Donna Summer's I Feel Love which was released by Giorgio Moroder in 7- and 20-minute remixes in 1977. Besides it's all computer-driven. Although I may be wrong. 
Ok, NO's dance "influence" unleashed after Blue Monday and that's 1983. Some may say about EGG, but was it really that popular... Anyway by 1983 the ELECTRO dance music had been largely established: disco and NY hip-hop scene was quite impressing, new wave bands like the Human League, Depeche Mode - they all used computers straight away to compose dance music. I'm not saying they were that good at that but still.
Kraftwerk were genuine electronic pioneers, but hardly dance ones :)
So we're practically talking here about only Blue Monday to call NO the pioneers? Had they followed the same path but they turned to Lonesome Tonight, Love Vigilantes and so forth.
THOUGH to me they were dance pioneers in my perosnal point of view: before NO I didn't listen to dance/electronic music at all. They brought me to that kind of music. 