Thanks to Tracie for emailing in this recommendation: "Dairy-free gourmet cupcakes in Edmonton, AB – Canada! It's called Big City Cupcakes and they do nut-free, dairy-free, and egg-free. They also offer gluten-free!"
Unfortunately, their website was under construction when we visited, so I couldn't see the locations, but they seem to have various in BC and Alberta at the least. According to their website, they are "Canada's largest and fastest growing Cupcake Company." And they do boast their new "FREE" Cupcakes for Gluten Sensitive and Egg and Dairy Sensitive Diets.
See website for locations and phone numbers.