I use an H55 (via NZXT G10 adapter) to cool my Radeon HD 6850 (OC as far as it'll go for distributed.net crunching) and it has no problem keeping the temps & noise down at constant full load, even with the stock fan pegged to a low speed to keep things silent.
The radiator fan supplied with this GTX 1080 is not the normal H55 fan, so don't know if the performance is the same or not. The H55 should be fine for the GTX1080, though of course fan speed and noise won't be silent under full load, but shouldn't be annoying either. I'm sure it'll become clear in the reviews.