I have made many of these solar stills and they work even in Death Valley area of Calif but you will need at least 5 per person and they work best if
you find a area in a wash or dry stream bed with a rock out cropping that blocks underground water flow.
Two things i would add to the kit one is a small hand pump to transfer the water from the still to containers.
www.amazon.com...
And the other is 5 Collapsible-1-Gallon-Water-Containers
www.amazon.com...
This would allow you to build up a water supply over a few days then break down the stills and travel a distance.
Also these solar stills do not have to be small i have build one over 20 foot across. over a plastic lined water pond.
We had plenty of brackish water but got tired of hauling drinking water.
so we built a solar still to distill the brackish water.