I spent about an hour in the train room last night, adult beverage in hand, mulling over that exact notion. Of course I'd have to cut it in half and stand it on edge to get it through the door. Honestly, I made too many mistakes laying track. Ex: the passing siding by the coal mine is so short it's worthless other than for static display of rolling stock. The trestle bridge is a hump - so much so that the track leading into it changes angle so abruptly that I can't run anything with three-axle trucks. So I think I'll either leave it as is or slowly cannibalize it.Could you fit the existing layout into this larger space... ?
Again, that is where my head is at right now.