Since we can see in TOS that the visible deck height is around 10 ft, the full deck height must be a bit more than that. If the 289 metres TOS Enterprise could have 10 ft (without
"a bit more") decks, the upscaled version (327 metres) can have "10 ft plus a bit more" (11.31 ft) deck heights.
So if a 289 metres Constitution class could have 10 ft decks then, my choice would be the 327 metres version because it supports the visible deck height, has enough space between the decks and nothing looks too oversized (windows, bridge dome, shuttle bay ...). That's my reasoning.