Hi there.

We had a RAV4, 2001 model with limited slip-diff, which means the all-wheel drive locks if one or more of the tyres start to slip (like in sand, for example).

With it we went to a number of places around Botswana, from the Mokolodi nature reserve, to Khama Rhino Sanctuary and to the Tuli Block.

Khama Rhino Sanctuary is quite sandy (but doesn't have very deep sand like Khutse for example) but we had no trouble there at all.
Ground clearance on the RAV is not that great in general, so be careful with the terrain you're on. We also got all-terrain tyres for it, which helps with grip (and when you deflate them, you get better traction as well).

If your RAV has a dedicated diff-lock button (ours didnt), then you just need to gauge when you should turn it on.
Also dont overload the RAV as it doesnt have stiff suspension.

Its a great compact SUV and can get you to quite a few good camping/bush places in Botswana.
Enjoy and have a great time.