A tiny N scale layout can be fun, and can fit just about anywhere.
One caveat, though... 2x4 is the N scale equivalent to the HO 4x8, and has all of the limitations that come along with the 4x8... Tight curves, sharp turnouts, not too much room for scenery, etc. My suggestion is, if you have the room, upsizing to the hollow-core door size really helps open up possibilities.
...but that said, Cox47's layout above looks very well done, working within the 2x4 constraints quite effectively. It can be done, but it's a challenge. Good on you, Cox47!
