I have not coordinated any battlefield tours but I have served as the Vice-Chairperson for 2 conventions held at hotels. The hotels don't make money on room rentals. Food and beverages and banquet/conference and ballroom rentals are where they make their money and the banquets were the hardest part of the committee duties. The hotels demand a guaranteed amount of revenue from food and beverages and then it becomes a matter of selling enough tickets to cover that cost. Enough tickets aren't always sold and then the event and/or the person signing for it becomes responsible for the shortfall.
I was not at the the 2 Gburg retreats so I'm not sure what was done there. As an event planner,I would not be in favor of trying to schedule and manage a banquet or 2 unless they were also speaking engagements. If it's just dinner,I would prefer compiling a list of local restaurants then making group dinner reservations close to the event when a firm headcount is known. Most of the better hotels provide some type of breakfast for guests and I'm guessing that lunch is on the road.
We could reserve a smaller conference room to socialize and for authors and vendors to set up shop. I'm guessing we could stock that room with our own water and soft drinks too.
That's just some early thoughts on the matter.