jillian1977, if you are within the Return interval - because you just upgraded - perhaps you could return it for a larger model if they offer one.
A "footbox" is not something you add; it's just the lower part (about 2 to 3 feet) of the top quilt that has the quilt edges connected, like a sleeping bag. That "connection" can be sewn together, connected with snaps, or a zipper. In addition, the very bottom of the TQ can be sewn or have a cinch cord.
If your feet are poking out, the TQ is just too small. Whatever "MacGyver" you use to make it work can be a hassle every time you use the bag. The Vendor might say, "You knew how tall you were and you knew how long our TQ was ..." but the vendors I've worked with would take back a "just ordered" product, though you'll probably (and fairly) be out the shipping.
If you can't return it, and you wear a down parka in the winter, you could put that jacket around the bottom of the quilt. If it's long enough, it probably won't slide off if you don't move around too much.
What vendor did you buy from? What model?
