I think when you landing, you can carry some cash in US dollars . After you open a canadian account, you can wire money from US in case of emergency. BTW Buffalo accepts cashier's check in US dollars.
Depends on the bank and province, it takes 15-30 days to cash a US cashier's check and 15-40 days to cash a US personal check. But it's free.
Today I bought a money order in CAD from a bank, for my wife's application fee. The rate is 1.52978 and the comminssion fee is 20USD. So 60 CAD cost me 59.22USD. Almost 1:1.