[KiwiHopeful]

I've been through them, going up Route 1, and have visited Amberley beach as well.

They are what we in the US would call 'one horse towns.' Blink and you miss 'em. If I recall correctly, Amberley and Woodend (to the south) have little downtown areas and grocery stores. I don't believe there's much of anything in Sefton or Balcairn. Of course, they're not far from Rangiora or Kaiapoi for shopping.

As for the time it would take to Chch, you're looking at closer to an hour. I haven't driven it at what passes for rush hour here, but I've been stuck at a couple of the key roundabouts for 10 minutes at mid-day during mid-week, so it may take even longer.

That said, I wouldn't count out those locations as viable options. Again, it's going to depend on where in Chch you (or the OH) would be commuting too and how much time in the car can be tolerated.