Don't know any retreats off hand , but maybe a quilt show and classes would work for you?
The Mid Atlantic Quilt Festival is just around the corner - it's a well run show (quilts/vendors/classes), and and just a couple of hours away (depending where in Delaware you live).
http://www.quiltfest.com/activities.asp?id=8
Or Lancaster:
http://lancasterquiltshow.com/
Or NJ Quiltfest:
http://www.quiltfest.com/activities.asp?id=30
The two big PA shows are late summer/Sept (I think).
eta: Unless you really want to be in a class or sew on your own project for two days (and ain't nothing wrong with that!).