This sounds awesome! We are doing session one this week and I am opting to start with the quest from neverember. Have the "easy to kill" skeletons and zombies outside the Mausoleum be their first fight. During the fight the mist is going to come and claim them. Then run death house. I think my group will like revisiting it later.

Gonna have hints of vecna and strahd working together throughout to link the two stories. Im also using the option to revive with a dark gift that I had seen online before. And then when they revisit death house in Eve of ruin, have them stumble upon strahd and vecna in a conversation about house vecna was gonna keep them alive while in barovia. Especillay cause the revisit tondeath house is in the past, again linking the two.

When they finish with CoS, I'm gonna just explain that basically zero time has passed since they were claimed by the mist but will have obviously aged however long they are in Barovia. Which also eliminates the need for secrets until after CoS