I have done so in the past, but let me reiterate how important Ontario is for the Liberals to have any chance of defeating the Tories.
I applied a projection based solely on the most recent week of the latest EKOS poll, where the Tories only led the Grits by 1.2%, but had roughly the same lead (0.8%) in Ontario. The seat result? Not even close:
CON - 124
LIB - 95
BQ - 50
NDP - 39
This is the same seat count for the Tories as in the 2006 election, while the Liberals do 8 seats worse even though they lost by 6% that time. Why? In 2006, the Grits still carried Ontario by almost 5%.
I also made a projection adding 3% to the Liberals and subtracting 3% from the Tories in every region of the country. This gives the Grits a 4.8% national lead, but a dead heat on the projected seat count:
CON - 109
LIB - 109
BQ - 49
NDP - 41
Do the Liberals now need to win by that much just to get a seat plurality? My guess is 'not quite so': after all, the "Ontario gap," defined as the difference between the Tory lead nationally and the Tory lead in Ontario, is abnormally low in the latest EKOS poll. That figure stood at 0.4% in the survey, while in my current poll average, it is 3.5%. But even with an Ontario gap of 3.5%, the Liberals would need to win the national popular vote by 3-4% in order to tie the seat count.
Now, it is quite possible that due to random error, polls currently understate Liberal gains in Ontario and overstate them elsewhere. If that's the case, and the Ontario gap is roughly at the level of the last election (6%), then the required national popular vote lead for the Grits is even lower. But I'm pretty sure that unless a drastic relative regional change occurs, the Tories would win the seat count in the event of a tied popular vote at the next election.
Can Ignatieff deliver his home province? His job depends on it. (Although by returning to academia, he would collect a larger paycheck while barely having to do any work due to tenure...)