Lower carb frozen entrees are available at some Super*Walmarts in the USA but not in Canada yet.
The brand is Chef's Choice and they run about 3 bucks in Florida. Be sure to check for the low carb version as Chef's Choice makes regular entrees too. (I got this info from another board that is very reliable.)
To find a Walmart near you with groceries, just go to
http://www.walmart.com. If you scroll to the bottom of the home page, they have a store locator. All you need to do is put in your City, State and zip code, select "grocery" and it will show you all the Wal-Marts near you that have groceries.
Hope this helps.