I DM'ed Death House a couple weeks ago, and my players loved it. Particularly as I pulled the ol' switcheroo.
I have my own homebrew campaign world. I started the players off with very vague details. "You'll be traveling through a forest in [homebrew Tsarist Russian nation in mid-winter]. Your goal is to seek employment on the northern border, fighting rebellious humanoid tribes. Pretty much any character concept will work. Go for it."
So the guys are immediately thinking: Keep on the Borderlands style. A few groans at the table. "Kobolds? Again?!?"
I set the tone early. I cracked out my new Dwarven Forge set of scenery: a tavern interior with [LED] candles flickering on the tables, rows of ale steins, and the most suspicious looking minis I could dig out for random travelers. The party heard a rumor that a small village to the east was seeking help for a minor problem. The players nodded sagely at each other. This was the expected side-quest that would get them to 2nd level, prior to the proper start of the goblin-fighting campaign.
Of course, things didn't work out that way. As soon as they enter the small village of Karlsworld (in my homebrew world), they encounter Rosavalda and Thornboldt... and Death House proceeded as written. This was a bit of a jolt for them. They did not expect a creepy old house where the first couple of floors were completely devoid of combat encounters. What kind of D&D session was this where there wasn't room-to-room combat?
I even took some of the (few) combat encounters out of the basement. The fewer the combats, the better, in my opinion. Pick any one of the combat encounters listed, and add the final one in the basement, and you're good to go.
To add tension, I had the house burning and collapsing around the PCs as they escaped... forcing a 4e-style Skill Challenge. 4 successes to escape (for each PC, on an individual level), before 3 failures. Once 3 failures were hit, and for every failure thereafter, something nasty happened to that individual PC (rat attack, scything blades, collapsing walls). If the PCs stopped to loot or explore other rooms, 6 or 8 successes were required instead. Several PCs almost didn't make it out. One had to be dragged out unconscious by his buddies.
So... they exit the burning, collapsing building. Into a quiet, darkened, mist-shrouded village. They accost the nearest villager, a downcast old fellow, to tell him about what they saw in the house and to seek his aid in putting out the fire. He looks puzzled, and they turn to see the house is nothing but an old shell of ashes behind them. "What are you talking about, strangers? That place has been ruined for 30 years." Their confusion intensified as they suddenly notice the tall mountains in the distance to the west, and the slightly older and grayer nature of the village. "You look confused, strangers. Maybe you should sit down and catch your breath for a moment. Oh... and welcome to Barovia..."
The players loved it.
...
So, a quick summary of what made it work for me:
1) Started the campaign in a different setting; misled the players during set-up. Yeah, I know that's supposed to be a no-no, but it worked for my long-standing group because there's a high degree of trust. These are 20-year veterans. If I'd told them Ravenloft from the get-go, the party is just wall-to-wall clerics and paladins.
2) Death House as a planar bridging point worked wonderfully. The time-disconnect added to the creepiness factor. Their horrifying experiences inside the house were made even more disconcerting when they realized that the house was actually burned to the ground 30 years ago (in Barovia).
3) Removing combat encounters was critical. Death House is far from a dungeon crawl, but it could stand to have even fewer combats. Pick one or two fights in the house, and one or two fights in the catacombs (including the final confrontation). That's all that are really needed. Make the fights as hard as you need to. They should feel horribly dangerous. This plays into Old Bonegrinder as well. That location is basically one fight (maybe two at most) and, at 3rd-4th level, that fight will be balls hard. It's Deadly+ by the DMG guidelines, and it played that way for us last weekend. A six-man party of 3rd level characters with superior tactics barely survived the windmill. That's Ravenloft.
4) The windmill elements in Death House (sword hilt, deed, etc) are a really nice thematic link to Old Bonegrinder. As soon as the party heard (in Barovia) that there was a windmill on the road to Vallaki, they were incentivized to check it out. One of them was actually carrying the windmill-hilted longsword, although they didn't take the deed out of the house with them. This is very useful, because it provides experienced players another hook (other than "Escort Ireena to Vallaki") which takes them away from the Castle. Too many experienced players will simply assume they're supposed to rock up to Strahd's door on Day One.
). You could just start at LV 3 and you'd be fine.
