While I can't say definitively, I'm pretty sure the answer is "not work at all".
For instance, if you go over to the Succession Game forum, one of the big problems they dealt with is that savegames made by people who had Babylon as a civ (meaning people who bought the deluxe edition) wouldn't work on the computers of those without Babylon, even if Babylon wasn't a civ in the current game. Someone had to whip up a little utility script that would alter the savegame file's header to be compatible with everyone else.
Given that, I'd say the odds of the game automatically adjusting in the way you describe to be pretty low.