Without having seen a picture of the bed made up I would have thought the 1770mm was the max width of the bed not the length.
Generally you sleep lengthways to the trailer.
I just measured the width of the bed base of my soft floor camper and it is a little over 1800mm. The mattress would be about 200-300ish mm narrower than that.
Also just measured the real queen size bed upstairs and it measures 1510mm wide.
2040mm is the length of the bed upstairs and 2200mm is the length of the bed board in the camper.
So if the 3000mm is the overall length of the trailer in question then it still comes up short :D unless the drawbar is less than one metre long (not taking into account the bed overhangs the drawbar a little bit).

