Aside from all the "marketing" of Harv's air, with any school there is no guarantee. Be careful with international fees as well as some schools differentiate whether you are a Canadian citizen or international student. I'm currently on my way to completing my CPL here in Toronto while working full time. The job i have pays the bills, and i save enough every month to obtain consistent training, i have a degree and some security. When im ready, ill leave the business and pursue flying full time. This is something you should consider doing IN THE UK first.
Canada has a great aviation record and for us citizens once you have enough experience you can get into the regionals and work your way up BUT it is very competitive we dont have an abundance of airlines like in the US or UK - something you should consider.
Last thing ill say - i was told "there was a good chance after i complete my CFI rating id get a job" with my school. Its looking good now, but nothing was ever written on paper. Outweigh your risks and costs - especially of living and consider home first.