Hi Julie and welcome back to the Disney Parks Moms Panel.
Whilst I haven't seen any official announcements detailing seasonal operating dates for
Stitch's Great Escape!, there does appear to be some hours listed for this attraction on the Walt Disney World website.
For example, the attraction is listed as being open from 10:00 AM to 8:00 PM on December 18, 2016 to January 1, 2017 inclusive.
My best advice to you would be to check the Hours (which can be found on the right hand side of the Stitch's Great Escape! page of the Walt Disney World website) for the dates of any upcoming trips to see if the attraction is likely to be operating during your visit. Just click on the calendar icon and select the individual dates of your upcoming visit to see if any hours are listed.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma