I like to take simple white plastic dishpans. I will stack 3 together. All my tools, machine, fabrics fit into my sewing machine carrier. Once I get there, I put all the tools in one, fabric in one and the other one is for the cut pieces. They can be stacked if not needed. As others, label everything, take a cushion or your sewing chair. Take a variety of projects. Cut some, sew some, hand some. At the retreats I have been to the ironing station is usually a bottleneck so I don't plan a project that requires alot of pressing. You are lucky that it is a 30 minute drive. Pack your car with extras, you won't have to take them all in, only run out to the car if you change your mind about something.