Overnight, the eight hour block in a dark month
An overnight is a fixed block of eight hours at EUR 1,250 for one guest with one therapist, with a written start and a written finish agreed beforehand.
It is a format rather than a mood, and both ends of it are written down before anyone travels so that nobody is working out at six in the morning when the block finishes.
The four figures
Eight hours for one guest with one therapist is EUR 1,250. Two therapists attending one guest across the same block is EUR 2,880. Two guests sharing a single therapist is EUR 2,500, and two guests with a therapist each is EUR 5,760. Half of whichever figure applies goes ahead, because the block always carries a deposit whatever else is true about the booking.
Why December writes more of them
A night that gets dark at half past four and stays dark until eight the next morning is a long night to fill, and the eight hour block is the format that matches its shape rather than fighting it. More of them are arranged between the middle of November and the end of January than in any other stretch of the year, and the second most common month for them is a wet October.
What the room needs
Heating that will hold through the small hours rather than switch itself off at one, which in a hotel usually means checking the panel rather than assuming. Water, because eight hours of a heated room is dehydrating. And a realistic view of sleep: the block is eight hours of held time, not eight hours of continuous work, and how it is used inside those hours is agreed between the two of you. The overnight page covers the rest.