How do you as a DM handle the transition/interaction between differing cultural level domains that live alongside (practically bordering, thanks to the Mists) one another in Ravenloft (any edition)?
I mean, for example, how do you make traveling from "Renaissance France" to "Medieval Germany" not break your (the players', the DM's) suspension of disbelief? (...let alone these domains trading with each other, (lack of) cultural influence - dressing, habits, sciences, architecture etc -, and so on.)
("Default" DnD has, thanks to its many illustrators a cultural "look and feel" that distantly (rather distantly!) resembles Earth's medieval period, but RL seems to rely more strongly on real historical times, which I'm not sure I like.)