The pair were crossing State Highway 1 when they were struck by a vehicle just before midnight on Saturday.
Roebuck, 70, died as a result of his injuries and Louise is fighting for her life in the intensive care unit at Waikato Hospital.
Roebuck's son Ant said the pair had travelled from their home in New Plymouth to Tokoroa in a party of three couples driving campervans for a festival in the south Waikato town.
After the festival, they went to a local pub to watch the Bledisloe Cup test between the All Blacks and Australia.
They were heading back to their campervans. which were parked around 400 metres from the pub.
Ant said they were crossing the road at a pedestrian crossing when they were hit by a car coming around a corner.
"[Louise] is in ICU at the moment so it's a little bit hard to speculate how she is at the moment with what's happening.
"She's had a couple of pretty big operations and she's got a couple of big ones to go. Obviously, if she's in ICU it's still pretty serious.
"We're just spending quite a bit of time with her and trying to get her through everything. Then we'll concentrate on a funeral after that."
Police are still investigating the crash.
The couple had been together since the early 1990s. Roebuck had three children from his first marriage: Ant Roebuck, Sharn Roebuck and Le-arna Russ, and Louise has three children: Jason Morris, Ben Morris and Amy Morris. Roebuck had nine grandchildren.
"His death is not going to affect the family, it's going to affect the community," Ant said.
Roebuck had been in construction before he retired in 2014, with Ant taking over the business.
The family has been a major player in the New Plymouth construction scene when Roebuck's father started Roebuck Construction in the 1960s.
Earning his apprenticeship with the company before heading to Australia, Roebuck returned to start his own business around 1979 in New Plymouth.
"He had that until 2007 and at that time I went into partnership with him and we had a building business until 2014 when he retired," Ant said.
"Then I closed it down and started up a business under a different name. It was K&A Roebuck Construction - which was Keith and Anthony - I thought that was not quite right and went back to the original family name which is what I still run today; Roebuck Construction."
Roebuck had two other loves - Surf Life Saving, which he coached and competed in, and watching the Tukapa senior men's rugby team.
"He never missed a Tukapa senior rugby match," Ant said.
"That was his real thing, every Saturday going and watching the seniors play their rugby.
"This year they won the competition, which was just awesome for him - he got a lot of enjoyment out of that."
Louise was a driving force behind the youth outreach hub in New Plymouth called Waves, which opened in 2006.
Ant said she put in a lot of hours into the programme and both she and Roebuck were "very very generous with their time".
Asked what they'll remember of their father, Le-arna said he gave the best advice, Sharn said he was her inspiration and mentor, and Ant said his father was always his port-of-call when he needed help.
They say there has been a massive outpouring of support since the incident.
"We've had just unbelievable support messages, hundreds a day," Ant said.
"We've tried to reply to most people but it's been pretty hard because he was so widely known that it's been unbelievable how many messages of support there's been."
