I frequently have multiple potential itineraries for a trip and will have hotel reservations booked for all of them in advance. As my trip gets closer, I finalize my plans and then cancel the reservations from the other other potential itineraries. I try to be good about it and do so at least a week in advance. Sometimes, I may not know until the last minute and may only be canceling a couple of days in advance. I always comply with the cancellation deadlines. I have done this for many years. I have never had any consequences from the hotels (at least none that I am aware of). YMMV...

--Jon