I am from the area. By Lancaster - do you mean the city or the County? There are many, many quilt shops in Lancaster County, but I can't think of any in Lancaster City itself. Maybe someone else knows of one.
There are a number of quilt shops in Intercourse, which is in Lancaster County. Do you know the name of the town you will be staying in?
Closer to the Show is The Quilt Block, which is on the same road (Rt. 113) as CCQ but further south near Rt. 100. There is also a shop called Generations in Pottstown, right off Rt. 422.
Oaks is about an hour away from Lancaster and Intercourse. So, depending on where you are staying, I would have more suggestions.
Oh - there is Steve's Sewing and Vac Center on Rt. 202 in King of Prussia. It is north of the Mall, which is also on Rt. 202. They are the shops closest to the Show. And the Mall is Huge and worth a visit.