Depending on how you measure it, including the tongue usually adds 3' feet. So you want a trailer that is 13' including the length of the tongue?
I believe the Metzendorf is 6' tall according to resources. Including the tongue will probably set this trailer at 15' guesstimate.
I know the trailers pictured below may be longer than 13', but I wanted to show them off just because I like the low profiles.
It's not a canned ham, and did not put a tape measure to it, but Eddie M. 1945(?) covered wagon may fit in a garage, a tad longer than 13'(?). The back door has a dropped floor that hinges down to the ground giving a standing area around the kitchenette. I should have taken pictures of the interior, because it is a really nice one!
One of my favorite 1947 homebrew trailers with dropped floor, again not a canned ham, but a little more trailer on the stretched length. Has a dropped floor that can be raised/lowered.
Or, there are a few fiberglass trailers like the Compact Jr., or Scamp, 1970's ish. I will have a Compact Jr. up for sale soon!
Photo not my trailer, but a good representation with the popped top.