I don't have a specific site but an idea for you to consider. My guild goes to a church camp off season, October and March. They have a beautiful large building where we quilt and can leave all of our "stuff" safely overnight. They have spartan hotel type rooms (bathroom, shower two double beds per room. No phone or TV.) It is a 3 minute walk from room to conference center and our work. The property is on a lovely large natural area where we can take breaks and walk. We feel like we are hours a way from home but in actually we are on 15 - 30 minutes away.
It is worth looking outside the traditional quilt retreat facilities and often much cheaper. We pay $70 per person and we potluck evening meals and bring our own breakfast.