In the absence of any other replies from people with actual experience of that charger...
Yeomans Nissan PO7 7XW - electric car charge points comments say open 24/7
PlugShare - Find Electric Vehicle Charging Locations Near You comments also say open 24/7
Instavolt rapid just over the road, as an alternative.
Sorry to answer an old query but I just stumbled across this thread looking for a different dealer's charging arrangements.
Yeomans of Waterlooville (aka Nissan Portsmouth even though they're 10 miles away !) used to make their rapid charger available 24/7. That changed to 'office hours only' in Nov 2018. But as TVEV pointed out there is an alternative rapid charger on the nearby petrol station forecourt. Alas, they're not free and probably don't do complimentary coffee either so I'll try & get to Yeomans during their opening hours..