Yes, one might expect special consideration given the volume of business. However, many hotels are franchises and therefore a bunch of small businesses. IF you are considered a HVC with the franchise they will most likely work something out. But given you agreed to the rate when booking and the need to change is not due to a property issue, they aren't likely to give in.
Doing the math, you may want to consider to NOT check out and just burn the night. Leave when you want and get the credit for the extra night (especially if not staying at another property that night).