Do silicone baking mats come in 14x16" sizes?
Don't know if you got it yet, but I just purchased one from Kohl's. It's a Food Network branded product. I had hoped for two, but store only had one.  There's some issue with the SKU from the bar code on the product, but they do carry the product.  Here's the link. http://www.kohls.com/product/prd-756153/food-network-14-x-16-baking-mat.jsp 
Here's the SKU that they had to look up in the store to ring it up:  91482863.  You can look up if your local store has any in stock, but not the quantity.  

Wish I had it yesterday before I baked three hundred cookies.  I'll be ready next year.  Tired of cutting parchment and it sliding around, especially with balled dough cookies!