I just returned from our guild's retreat. I suggest finding a rolling storage crate (like teachers take to conferences) to put all of your things in such as your box of threads, your notions box with needles/blades/pins/etc, your project boxes or baskets. Not only does the larger crate help you keep your stuff together, it also makes the transportation from the car easier. It also makes the unloading the car at home easier, too! I had my rolling machine tote and my rolling crate tote and that was all I had to take in. Here is a link to several choices; I love the one with the outer pockets!
http://www.amazon.com/s/?ie=UTF8&key...l_7rbufnkurr_b
Something else to be sure to take is a chair cushion. Not only does it soothe your buns, it also helps to raise you to the correct height for sewing.
Have fun!!!!