What a great party! You mentioned the ranger was human; what were the races of the other characters?
Adding in some more details... They were all 5th level at the start.
1) A conjuror entertainer who had assumed the identity of his late Romani wizard friend. So a mysterious magician like Mr. Dark. His assumed name was Spiros (I forgot his real name); he was half-elven, and he had the conjuror path of wizard. As magic items I gave him a Serpentine Owl figurine and an Orb of Darkness (darkness at will centered on the orb).
2) A Van-Helsing-like cleric of light, dedicated to hunting down the undead. He was named Heinrich Von Lutgher, a dwarf, and dedicated to Lathandar. As magic items I gave him a Staff of Healing and a Wand of Secrets.
3) A guilt-wracked Shadar-Kai monk, who owed a life debt to a family in the region. The Shadar-Kai are a sort of elves from the Shadowfell, in league with a demi-god, the Raven Queen. He had awoken without memories a few years earlier (common for his kind), and was taken on as a bodyguard by a young noble. However, he failed and was going to the noble's kin to offer his services. His name was Arai, and he had the Kensei monk path. For magic items, I gave him a +2 longsword.
4) A down-to-earth human ranger, defending his home and family. He had an older sister who had married someone in Barovia some twenty years earlier. His name was Beauregard, and he had the Natural Explorer path. For magic items, I gave him Bracers of Archery and a Lantern of Revealing.
5) A gentlewoman arcane trickster, who steals from the nobility she poses among. She was a high elf, and had a supposed connection to the local nobility. Her name was Katarina Belview. For magic items, I gave her Boots of Levitation and a Bag of Holding.
Their connection meant that I also gave them a bunch more starting information. The dwarf had been from the region, so he had ancestors who had built Ravenloft itself - so I let him roll History to remember architectural features. The wizard was welcomed by the Romani, so they gave him extra background. And I added in to the background that Ravenloft was originally dedicated to the demi-god that would later become the Raven Queen -- so there was a mystic connection for the Shadar-Kai.
Have you seen the 5E version? I own it, but not I6, so I don't know how the two compare. I do have the 3E version, which had a completely different feel than the 5E. Less evocative? Hard to say, but it felt like it was missing something. The 5E version also has that feature where the cards decide the adventure, such as where Strahd can be found. It also has many side adventures in Barovia. You could spend half a year and not even get to the castle, which some people might consider a minus rather than a plus.
I've only briefly skimmed the 5E Curse of Strahd adventure at a store. Since this was an adventure for a two-week family vacation, I thought taking a year without getting to the castle was more of a minus. I had run I6 Ravenloft decades earlier - at least once during college and once during grad school. I still had my copy and had always liked it. The original has only a brief setup - there are a half-dozen locations in the village, then the gypsy encampment outside (half a page), and then the castle itself, which has 88 locations but many are uneven. It's pretty tightly put together, but has a lot of room for DM improvisation mostly in what Strahd does - which should be based on his plan.
What I really like about it:
- It's a dynamic module, one of the first of its kind that way. There are keyed locations, but the core of the adventure is playing Strahd as a mobile NPC with a goal and resources to achieve it.
- As mentioned, there is the card reading to tell where key items are and what Strahd's goal is. This doesn't give control to the players, but it gives them information. It also means that none of the encounters are designed around a particular storyline, because there are a bunch of different plot options.
- The flavor is excellent. It hits on a bunch of classics of gothic horror without feeling too forced.
- The maps are a joy, particularly in that they form a castle that makes some sense in architecture, so it's easy to convey more of the feeling of being in a real spooky castle. Spooky castles with a dark history are a central part of the gothic genre, that nicely merges with the D&D style of exploration.
I had bought a PDF that had battle maps for every room in the castle, which I had printed out. That made mapping/drawing quicker, and the rooms looked nice.
https://www.dmsguild.com/product/254681/Castle-Ravenloft-Battle-Maps