With that kind of scale, we could almost justify the 20-deck saucer from the early TOS eps, based in-turn on an early rev of the writer's guide.I vaguely recall reading that it was 150% of the 947 foot length, which would be 1420.5.
Amusingly enough, I believe even at that size the original shuttle hangar model (as first seen in "Galileo 7") is still too big to fit, if I recall correctly, it needs to be closer to 1600 feet to accommodate that model.