In the following escape rooms in Dover (VT), you must purchase the entire experience at once. You'll only play with the members of your own team and won't be paired with strangers.
The only requirement is to meet the minimum number of players for the room — the price is usually set for the room itself, though it can also depend on the number of players.

Can you find Smokey’s Schlitz and win a one-song dance party for your team?
Sherlock Holmes was working on a diamond theft case and has been captured in the process.