If you rented the room it's YOUR baby. If you scrounged it, it's theirs. Simple at that.
Interesting how that works... but I think you're right, Wilhelm. All one needs to do is get "the right" room!
Just rent the room.... for your anniversary! You get the shot you want, you impress the little woman, everyone wins!
Real cameras are measured in inches...
"Intention of use": maybe they will see it as a nice gesture from you, but in fact their agreement is irrelevant. It is your image, the hotel is not in it, so you can do whatever you want with it.
"copyright release": that's the wrong term. This is called a "license". Stating that you can revoke an agreed-upon license is not going to fly.