The first riders back don’t have to wait for the last.
If part of the group is visiting Wheels Through Time and the others want another hour on the road, skip the formal curtain time. Set my table inside the lodge where you’re hosting supper. The first people back can watch a round with the dice. When the next pair arrives, let the first witnesses explain the rules. I particularly enjoy the part where the witnesses realize that knowing the rules has done them no good whatsoever.
A bar bet works perfectly well without a bar.
Guests can call the outcome, keep an eye on my hands, or stand behind a friend and offer magnificently unhelpful advice. Nobody needs a drink, nobody puts down money, and nobody has to give up a conversation to be polite to the magician. A spare table near the common room works better than the only place people can put a plate.
If several cabins are sharing the weekend, send the address of the lodge where everyone will meet, not the cabin where the organizer sleeps. Confirm you have permission to use the common room and tell me when supper comes off the grill. The cook deserves an audience, too.