I would suggest you have got a snowball in hell’s chance of people moving over to let you pass If they are holding you up.
These are most likely the same people that can’t keep left on a two lane road, let alone maintain a speed near the limit.
And as for multi lane motorways, absolutely no chance, sit in the middle lane at about 20km/h below the limit to be “safe”.
The driving standards in NZ are getting worse by the day, no point worrying about speed limits when the majority of drivers don’t have the basic skills necessary for daily driving.