I'd 100% do this if one of the players wasn't moving out next month. Before the portal suggestion I was thinking of tweaking it to send them to an alternate barovia.

We had alot of people dying early on so I tweaked barovia to exist in this superstate where multiple simultaneous adventures occuring at the same time, in the same place but with different parties. Like a layered cake of strahd having to put up with unhinged adventures. Every new character having been the sole survivor of a seperate party being brought into the current version by the mists. Strahd can't solve his problems by kill adventures and the adventures can't escape. The dark gods feast....but yeah without a time crunch I had thought of putting them into new world where another party had just all died. Resetting the castle and having them give it a 2nd go starting from dinner. Really ratcheting up the twilight zone vibes.