Planning vs. packing

Research question: Can I bring a carload of party gear and a passenger to Baycon? I'm trying to figure out how much space the coolers and other stuff will take up, so in May I'll be prepared.

I'm going to pack as many things in bags as I can. Hoping to have the back third of my cargo space filled with coolers, boxes, and most of the rigid bulky things. Then the forwards two-thirds will have the cart and all the bags.