I think you're defining puzzle too narrowly. There is one solution in CoS -- Strahd must die. Unless you're changing the module to alter Strahd, he's not available to be negotiated or reasoned with -- the only way out is through. That you can accomplish killing Strahd in many ways doesn't remove the fact that the puzzle to be solved is how to kill Strahd. And, usually, the solution set looks very much the same between tables -- you get the geegaws that help, confront Strahd in his castle, and kill him.
ETA: look, this isn't a dig. It's a frank assessment of play. This is exactly how I present my 5e games.