Check the closing times posted at the FtW boat dock after you arrive at the resort. The boat from MK runs until 1 hour after MK closing; the boat from CR has a set closing time, but I can't remember what it is.
Also check the resort-wide Times Guide after you arrive for the monorail closing times, which vary by time of year. You can pick one up at any resort, including the Concierge/Info window outside Pioneer Hall, or you can probably ask for one at check-in. It's different from the individual park-specific Times Guides, and lists hours for transportation and all parks for the week (Sun. thru Sat.) You can see an example of this weeks edition
here.