The Minority language

It is the first time in my life to realise the difficult position I am in as I am the only Cantonese speaking person for Jasper, everywhere else is English including the TV !!! A lot of friends who had mother-tongue spoken at home 100%(ie both parents) when they were babies and still not speak that language when they are in adulthood. They have at least 3 more interactions of the minority language(Cantonese) than my family: (1)mother-to_baby, (2)father-to-baby, (3)mother-to-father, other grandparents-to-baby etc. I don't know what would be a realistic goal for Jasper's Cantonese, but i know that full literacy or even fully verbal would be a lot more difficult to achieve than other family with a single minority language spoken at home. Then Jasper's parents-in-laws are starting to speak their heritage language to him and they(MIL etc) are second generation turkish-cypriots moved from London to Australian before raising the family. If I use the "one-person-one-language" method throughout his babyhood, I dont know what the family language would be when he grows up..... the thing is that I have been so 'bad' as I have been speaking 20% Cantonese and 80% English to Jasper.