If anyone is concerned about filling a huge bag, consider getting a smaller OOT bag. I ordered these from Oriental Trading. I'll be giving one per person and I should be able to fit a travel mug, a few snacks, some advil, pepto and our itinerary in it.
The "fabric" of the bag is almost like a rubbery/vinyl texture so I thought it would be great to put a wet suit in if our guests decide to swim the last day before heading home.
Bright Stripes Tote Bags
Bright Geometric Tote Bags