One of the comments I had read was by Elsa:
It is stated on the website for Mapungubwe that they do them.
Activities offered
Bush Braais
Experience an unforgettable game drive ends in a dinner in the bush overlooking a dam, surrounded by burning lanterns whilst listening to the sounds of the bushveld and distant animals calling. A minimum of four and maximum of 20 persons can be accommodated, with an age limit of six years. Bush braais must be booked and confirmed a week in advance.
I found out costs and other details, checked with all of my trip companions, and booked and paid.
On the day of the braai, we had to be at the entrance gate (all activities leave from the entrance gate), and we left at 4 pm for our game drive which would end at the braai site. After an interesting drive we passed the dam turning and, further on, turned down a little, rough road towards the river. We immediately came upon a road block, three large ellies of which one decided to continue down the steep part of the track ahead of us, and took his time getting out of the way. Eventually we were able to pass him and came to the river, and stopped on the bank above where the staff had set up everything ready for our dinner on the river sand.
It was getting dark, the sunset was a line of orange colours on the western horizon....
....and these scenes met our eyes.
They had made a fire on the sand, a little way away from our table, which added to the atmosphere.
One of the bakkies was parked on the sand and they served most of the food from there.
Our dinner consisted of a starter of small pastries and finger snacks, followed by the braai of chicken, a pork chop and wors, grilled to perfection, and accompanied by about six side dishes including creamed spinach, pumpkin, chakalaka and mealie pap. Dessert, when we barely had room for another morsel, was a delectable little portion of red velvet pudding. Cooldrinks and bottled water were on the table, and those who wanted wine or other drinks brought their own.
There were two serving/cooking staff, a ranger with a rifle for just in case, and our driver, but it was only us humans in the river bed that evening, enjoying a very pleasant African dinner on the sands of the Limpopo.
It was a lovely surprise to be taken to the river instead of the dam, which made for a very special occasion.
A big thank you to everyone involved.
Other guests are interested in this, as there are only three of us. 
