While guessing (or estimating) the number of ITAs based on the immigration level plans (projected admission targets, i.e.,
300,000 admissions for the year 2017), just keep in mind that IRCC already has a huge inventory of pending permanent resident applications,
371,909, as per the latest data release (including applications submitted through the Express Entry and also the non-EE applications).
[Permanent Resident: EDW (PR Datamart) as of August 8, 2016]
Permanent Resident Inventory (In persons)
Overall 371,909
Economic 141,688
Family 136,935
Humanitarian 93,286
Also, it's up to IRCC what percentage of the annual targets they allot to the pending applications from the existing inventory and what percentage they would allocate for the new applications coming through the EE system. So, there is no way to estimate how exactly the ITAs and the draw cutoffs are going to be. But one thing is pretty clear, more admissions (higher targets) means more spaces and more chances, so if annual immigration levels increase, it means there would be more chances for everyone.
To get a good idea, as the overall immigration targets for 2016 and 2017 are pretty much the same (i.e., 300,000), there won't be much of the difference. However, as there is a slight adjustment in numbers for different categories (slightly higher economic targets and less humanitarian), and as IRCC plans to admit more people through the Express Entry in 2017, one can assume that there would be more chances through the Express Entry system.