Hellobee Boards

I have a really big sofa and found the pottery barn slipcovers work really well. I don't think they make them anymore, but you can get them on uglysofa.com (the loose fit ones) or on eBay. I prefer the separate seat ones (they have basically a fitted sheet that goes on the seat cushions, so the whole thing stays together better. I use the large sofa--i can measure if you want.

This is the one I like (they also have ones for the t cushion sofas, where the seat sticks past the arms): http://www.uglysofa.com/products/Separate-Seat-Square-Cushion-Slipcover-Large-Sofa.html

I have this one from Target - https://www.target.com/p/gray-oxford-2-piece-sofa-slipcover-sure-fit/-/A-14711873?lnk=rec|adaptpdph1|related_prods_vv|adaptpdph1|14711873|0

Oddly enough I'm actually selling the couch and loveseat one right now as we are getting new furniture.

@Mamaof2: A lot of stretch! I think it would definitely work.