It could be that Bernier will do the expeditious thing and renege on his platform should the Cons anoint him.  But the bluster so far suggests quite the opposite, and his unwillingness to compromise for Harper make your scenario unlikely.  He has stated he would allow a free vote on abortion and has been more or less unwavering on the flat tax scenario.  Neither position is likely to win his party enough support to even have a hope of forming a minority.

Scheer, Chong, O’Toole or Raitt might have a shot in crafting a position sufficiently centrist to attract enough votes to make the CPC a contender.  I don’t think Mad Max has enough compromise in him to achieve that.