The Dark Blues' assistant boss stepped up to replace Andy Robinson as a temporary measure after the disastrous Autumn International series forced his resignation. Since then, he has guided the nation to two wins from four RBS 6 Nations games.
Scotland will now travel to Paris this Saturday hoping to make it three wins in the tournament for the first time since 2006, but interim head coach Johnson told Press Association Sport: "This ride is not about me. It's about Scotland. I've got a job to do and that is to prepare for a World Cup, whether I'm there or not."
He added: "It's important for Scotland's development that I get that part right.
"I will review it with the appropriate people at the end of the campaign, like I said at day one. We will sit down and decide what is in the best interests of Scottish rugby."
Scotland lost all five of the Six Nations fixtures last year and were humbled 21-15 by Tonga at Pittodrie in November - the result which ultimately forced Robinson to fall on his sword.
But wins over Italy and Ireland as well as competative displays against England and Wales have shown promise.
Johnson, though, insists there is more to come, saying: "There are some things I'm really happy with at times and some things I think have gone back a peg or two.
"It's been really hard to judge because we haven't been able to play the way we want to play. Some of that is our fault - we accept that.
"Some of it is out of our control and that is the frustrating part from our point of view. So we have got so sort that out so we are more in control."
- Sports & Recreation