Most camping stores, or places that sell camping supplies and such sell a kit that can be used to repair rips. I had an army tent for years; I swear I could park my wives Toyota Celica in it, and still have room to sleep 6, along with the picnic bench inside! I had so many of those "iron on" patches on it over the years, and it never leaked through them.
As an idiot, I lent it to a work friend to use for his family camp out adventure. That was 8 years ago; he moved, and I have no idea to this day where he and that tent now reside.
May not look pretty with a patch, but it would work. To keep it new, I'd find someone to replace the entire panel.
Then to help protect the canvas, consider buying a set of "POPUPGIZMOS" bunkend covers: