I would answer No for most parts of Ontario. They are not particularly hardy for our climate. For Niagara, there’s a different answer – you can try. The nearby Trillium Hill Garden Centre had some bulbs in the compost pile a few years ago and they bloomed the following year.
One of the problems is that Easter Lilies do not really bloom at Easter, so they have been forced by the florist, which makes it hard for them to make the transformation into a thriving plant in your garden.
Another concern is that Easter Lilies can bring the lily beetle with them in the soil, so there’s a caution about introducing them to the garden.