I tagged along to the Coningsby nightshoot a few weeks back. A night of mixed feelings as I had a nightmare journey to the base, getting caught up in tons of traffic despite setting out in what I thought was enough time! I arrived at 6.13, two minutes before they shut the gate for entry! In addition, I was partway there when I realised I'd forgotten my remote shutter so most of my pictures were from using the in-built timer. I did however use my homemade bean bag for the lower shots which I was quite happy with! I also need a new tripod as my camera with battery grip is too heavy for it now! Maaaan, more expense!
Personally if I'm doing tripod shoots, I take the battery grip off. I find going back to the single battery isn't an issue as you're usually not taking as many shots as you might in a "hand held" environment.
Outstanding shots, looks like a good one to have gone to.