For a lark, let's look at the best and worst polling results each party has had across the country, and what that would mean for seats. In other words, based on recent polls (leaving their margins of error alone), what are the best and worst case scenarios for each party in this coming election?
Here are the high/lows for each party:
BC - 45% (June 4) and 26% (April 19)
AB - 66% (July 28) and 49% (September 2)
PR - 59% (June 29) and 32% (April 13)
ON - 43% (August 20) and 31% (June 8)
QC - 20% (August 20) and 8% (June 4)
AT - 42% (September 2) and 19% (June 21)
In all regions but Quebec, these results would be their worst or their best in the last three elections. The 20% in Quebec would be worse than the 2006 and 2008 results but would be better than the 8.8% in 2004. This shows how much ground the party has lost in the province.
These best case scenarios translate into 157 seats. This, and the projections below, need to be taken with a grain of salt as the projection works best when the party totals interact with one another. This is based on only plugging the one party's numbers into the projection. Nevertheless, 157 is a majority - but a slim one. This shows the Tories don't have too much room to work with if they want a majority.
Their worst case scenario would be a dismal 69 seats. Still enough, however, to form the official opposition.
BC - 36% (June 21) and 19% (August 26)
AB - 26% (June 18) and 12% (June 18)
PR - 39% (April 13) and 9% (August 20)
ON - 45% (April 5) and 31% (August 20)
QC - 38% (June 1) and 23% (September 6)
AT - 48% (April 22) and 23% (July 17)
These would represent best and worst performances since 2004 except in Alberta, where the 2008 result was worse, and Quebec, where the 2006 result was worse. This shows the Liberals have gained some ground in Alberta and Quebec.
Their best case scenario gives them 148 seats, so no majority. Their worst case scenario gives them 58 seats. An opportunity for the Bloc to lead the opposition like in 1993?
BC - 33% (September 2) and 14% (July 3)
AB - 19% (June 18) and 6% (April 13)
PR - 35% (September 2) and 11% (June 4)
ON - 20% (June 18) and 10% (June 7)
QC - 18% (August 23) and 6% (September 6)
AT - 35% (July 17) and 17% (March 8)
These would all be worst and best results since 2004, except in Quebec where the 2004 result was worse than 6%. This shows the NDP has made itself into an option in Quebec.
Best case scenario gives the NDP 47 seats, still unlikely to lead the opposition but likely to take over the Bloc as third party in Parliament. The worst case scenario is 13 seats. Considering the NDP has recently spent some time with single-digit seat totals, that isn't a horrible result.
The Bloc's best polling result was 49% on September 6. Their worst was 30% on August 23. That gives them a best case scenario of 54 seats and a worst case scenario of 39.
I only looked at their best polling results, which were 24% in BC (August 23), 18% in AB (May 29), 16% in PR (May 3), 15% in ON (August 26), 11% in QC (June 7), and 14% in AT (May 29). That gives them two seats - one in British Columbia (Ms. May) and one in Ontario (Guelph).