Hi dpd,
Welcome to the Mattress Forum! 
The focus on this site isn’t on searching for “discounts”, but instead on educating people to assist them in making informed decisions when mattress shopping, hopefully starting with the information contained in the mattress shopping tutorial.
But subject to first confirming that any retailer or manufacturer on the list that you wish to visit is completely transparent (see this article) and to making sure that any mattress you are considering meets the quality/value guidelines here … the better options or possibilities I’m aware of in and around Winnipeg are in post #2 here.
I hope that helps you out with your search.
Phoenix