I recently picked up a medium duffle and went on a 4 day trip to the US for a bud's wedding. I packed it with a pair of Alden boots with trees, 3 crewneck merino sweaters, 2 pair of denim, underwear, socks, tees and two button down shirts and a hoodie. Suit was in a suit bag so not in the duffle.
I noticed there was still lots of room in the bag.
Wish I had taken pics.
Hope that helps.