With ACT now a walking corpse, National is looking for potential coalition partners for the future, and has signalled that it could work with Colin Craig's Conservative Party. It makes sense for National - parties with no friends simply don't get to be government - but it would mean quite a shift. Most obviously, the Conservatives are anti-privatisation - meaning that any future National / Conservative coalition wouldn't be selling New Zealand assets. Which may explain why National are so keen to sell stuff now: because it’ll be the last chance they get.
The other problem is of course that the Conservatives are a Christian Party, led by a pro-child-beating fundamentalist, and staffed largely by former members of the Kiwi Party (who in turn were the Christian faction within United Future, and before that called themselves the Christian Democrats). While we've seen some of these people in Parliament before, its fair to say that it was because they were very quiet (some might even say "deceptive") about their beliefs. The New Zealand electorate tends to be quite suspicious of explicitly religious parties, and so climbing into bed with one is a political risk for National. And actively endorsing a Conservative candidate, in the way they have repeatedly endorsed ACT in Epsom, could backfire badly. But when you're a big party with no friends, you don't really have many options.