Join Date: Feb 2006
Location: Cockeysville, MD
Programs: Marriott Rewards Lifetime Titanium, Amex Plat, Hertz Gold 5*, National Exec, AA Plat
Posts: 9,501
Any "fee" would depend on the cancellation policy of the particular hotel.
Some let you cancel up to 6pm day of arrival, some 14 days or more.
You may get some sympathy since you are changing-not cancelling, but nothing is guaranteed.