Rob28 said:
Are we gonna be able to do all 7 houses in one night?
I think that would be a difficult task, if at all possible. I would suggest that you watch the shows in the daytime, because you probably won't have time for both after the event starts officially. My strategy for Howl-O-Scream is as follows: First, I head towards Bitten. Bitten has shorter lines when it first opens, because people usually take longer to get to that area. I assume that rule will also apply for the new "LumberHack" maze, since it's in the same general area.
Right after you are finished in Festhaus Park, go to to "Cornered". That will have a long line before it opens, but they usually get the flow going after half an hour or so. After that, it would be a good time to backtrack. Although Catacombs is the closest maze, it will have the longest lines in the middle of the evening, so wait to do that later.
Instead, go to either Cut Throat Cove or Deadline. I would start with whichever maze you want most between the two. Cut Throat Cove should be dark enough by now, and the line should be moving at a good pace. If you have to buy a single-house quick queue ticket, buy it for this at the Tempesto/Apollo's Chariot gift shop.
Now that Cut Throat Cove (if you opted to do that maze) is out of the way, head over to Deadline. This line usually moves very fast even if the queue looks full. Once this is over, you should still have some time to spare.
Since you have to go through Ireland to finish the last two mazes, check if the wait time for "Unearthed" is still long. If so, go towards Catacombs. The line for Catacombs is usually dead (no pun intended) at the end of the night.
By now, your time will probably be running out, so hurry (don't run) to "Unearthed." The line may still be long, depending on the popularity and other various factors during that night. However, once you are in a line for something, they will not kick you out. I know there have been many cases where employees have had to leave the park at 2 AM due to the excess number of people waiting in line for mazes in that building.
Now, if you were successful, congratulations! You have completed all of the haunted houses in one night! Remember, the shows are also very good, and definitely worth seeing, but try to do those mostly before 6 PM, or you might not have time to do all of the houses without sacrificing one or two.