Mentoring a Novice Woodworker - A Linen Cabinet
Here's why the "Final Assembly On Site" is required. This thing will be big - to big to get through a door upright. Standing it upright in the room where it will be installed means it's minimum width or depth dimension DIAGONAL must be less than the minimum ceiling height under which it will reside. Assembled, if the diagonal has to be less than the ceiling height, you have to make the stiles (uprights) 2 1/8" or 4 3/4" shorter than the minimum ceiling height. So you'd need to use some fairly wide molding at the top and/or bottom - and there's that "distance to the door molding" constraint.
SO - the stiles (uprights) will be 95" leaving 3/4" minimum clearance to the ceiling, When shimmed to level in the corner a simple 3/4" tall half inch thick trim will cover the gaps top and bottom.
So if we allow at least an inch from the outside of the cabinet to the door molding we're looking at 30"w x 20" d x 95"h.