Originally Posted by
theoflyalot
I had a reservation for me and my S.O. at a hotel booked through booking.com (priceline), ....and the reservation was for a single. Does any one know what if anything governs the ability of hotel owners to limit the number of people in a hotel room? The hotel kept the payment since they consider this a cancellation. Am I S.O.L?
..
You didn't have a reservation for you and your S.O. You had a reservation for yourself.
Originally Posted by
theoflyalot
--> Because we are cheap

And we don't mind sharing a bed, especially when its an extra 100 euros a night to do otherwise.
Sounds like you intentionally booked a single, you knew it would cost an extra 100 euros to book a double and you decided to take your chances. You lost.
edited to add the way you worded your OP suggested you made an innocent mistake. That's not the case.