I was going to do sliding barn door for my entrance. There is a 28 1\2" opening in the wall. So I thought a 40" door would give plenty of extra space on either side for wind and snow protection as well as predator. With the brackets to hold it close to the wall that is.
View attachment 1562505
Don't mind the very rough drawing.
So the yellow part is filled in now. (Not in the picture.) Put the track where the blue line is. There is header there from it being a garage door opening. Then have the door be that green part. A good 5" extra on either side. Black lines would be U brackets to act as a stop on the right and hold the door back from swinging out to far.