I have just gone through this process this year. It seemed like ALOT of people were applying this year. There were definitely people out there that only applied to one or two schools, but there were quite a few that applied to many schools in and out of province. Several of my friends from med school applied, as did many people from my residency program (U of T)...4/15 residents at my hospital alone!
I spoke with the old program director at U of T (Dr Letovsky) and he said that people who applied broadly had a >85% chance of getting in somewhere....didn't specify what broadly meant though. I know for sure of one person who didn't get in but she only applied to one school. Most people that I know who applied got in somewhere, albeit maybe not their first choice.
This year there were around 60-120 applicants per school (anecdotally). You can take a bit of comfort in knowing that there is alot of overlap as many people do apply broadly.
If you want to strengthen your application, make sure you show interest and get strong reference letters. Don't put all your eggs in one basket. Working with program directors is great but not necessary. Try and do electives at the schools you plan on ranking highly to increase your chances of getting an interview.