Steph
Can I just make a suggestion as Olly says you must do what you feel is best.
The soft holdall is for the safari part, the jeeps do not have much room in them and it's a very long drive to the hotel. So space all round is tight thats why a smaller case for each person is better they go in the back of the jeep but NOT much room, Also there is not room in the jeep for everyone to have much STUFF just a backpack is about it. Take my word when your on the game drive you want as little as possible as you are up and down looking out the top so do not take anything you dont need in the jeep.
Also when your at the safari hotel as your sharing a room these are not big rooms to have lots of stuff in you really do need just want you want for them few days.
Leave all the other clothes etc for the 2nd hotel in the other case then you don't have to worry about all that stuff.
If your only allowed the one case I would just pack the few bits you need on safari into a holdall inside the BIG CASE then just remove that at the airport. Its very low key with clothes etc on safari so not much is required.
If I can help at all with anything just ask.OK. I wish you well it is a fantastic holiday and the animals are amazing.
Cindy
THANK YOU Cindy for your very helpful reply