Normally political parties getting 6% in a first past the post election in Canada do not win any seats, but in 2012 Quebec solidaire managed to win two seats and come second in three more and just barely break 6% of the vote. They did they through focusing their resources in a very limited geographical area. For them this strategy has been working and could lead to them winning as many as five seats in this election.
QS elections results
% of vote in
Elect votes pct seats top 5 seats
2008 144,418 3.64% 0 17.78%
2008 122,618 3.78% 1 20.36%
2012 263,111 6.03% 2 19.55%
What you can see is that the support for QS has been very concentrated in just a few seats and this is not the norm in politics in Canada. As a comparison, the percentage of the total votes for the four major parties in their top five seats from the 2012 Quebec election:
The five seats of Gouin, Mercier, Sainte Marie-St Jacques, Laurier Dorion, and Hochelaga Maisonneuve are located as block A number of the seats bordering these five are among the next best results for QS.
What QS needs to win the seats
Laurier Dorion 3,143 votes, 9.75 percentage points - Liberal held
Sainte-Marie–Saint-Jacques 2,946 votes 10.33 percentage points - PQ held
Hochelaga-Maisonneuve 6,053 votes 21.41 percentage points - PQ held
The task to win them will be difficult, but the track record for QS shows that for the first two they could be a threat to win.