I used InstaCart in January & was VERY happy with the service. I live in the US, so I am not sure if there is some reason that a Canadian can't use the service.
We chose Publix for our shopping. The shopper was texting me just as our flight arrived that he was selecting our items, asked me about a couple of switches he needed to make & everything was in our room at POP when we got there.
We ordered mostly breakfast items, snacks & drinks.