At this point it is unlikely that they will pull that off, but with our ridiculous system up here, it is not impossible.
With the polling numbers as they stand now, I think the most likely scenario is for the Liberals to form a minority government with the support of the NDP. That would not be a bad arrangement since both parties have polices that I support, and I am naive enough to think that they could cooperate as well as they have done in the past.
Less likely, but definitely possible is for the Conservatives to pull enough seats for a minority government, while trailing significantly in the polls. Our system is just shitty enough to let that happen.
In this event, the Liberals, New Democrats and Bloc have all been adamant that none of them will support the party, and do their best to bring it down on the first vote of parliament. To my mind, this is the second worst scenario behind a Conservative majority. When a government in a minority position gets brought down - especially close to an election - the election-weary public have a history of punishing the parties who forced it, and just giving a majority to the the party that previously held a minority.
Our parliament allows for coalition governments, but even though the New Democrats have tossed out the idea a couple of times during the election, Trudeau has been adamant that he has no interest in a coalition. I think it is a good strategy on his part, because it forces voters on the left to be a little less complacent, and a bit more strategic in trying to oust the Conservatives.
In the unfortunate event that the Conservatives manage to squeak out a minority, this is what I think the Liberals and New Democrats should do.
They should form a coalition government, but only long enough to push through the voting reform that they both agree is needed. They have been floating ideas of either ranked ballots with instant-runoff (my preference), or proportional representation (not ideal, but still a far cry better than what we have). They can make this kind of electoral change without needing to crack open the constitution, and it would go a long way to putting an end to the tyranny of the minority that we have been dealing with here since the 90s.
Another benefit is that it would force the Conservatives to move back toward the centre if they had any hope of ever holding power again. They would either need to pull a pure majority - unlikely given how radically they have moved to the right under Harper - or they would need to move close enough to the political centre to make themselves palatable enough for any party to support them in a minority situation.
That's what I would do. The meat-heads running the two parties on the left will doubtless just force an election if this situation arises.