My basic idea is to use similar functions, but turn it into a shelter by having 2 facing curved reflective sides that move to form a roof at night for a shelter. During daylight sunny hours the roof folds down to heat a plinth like in the Infinity bakery.
If a bakery is not required, ir could heat water or soil / brick blocks to store heat for the cold night ahead.
Edit: perhaps this plinth could form a work table / bed base.
2nd Edit: Having thought about the design for a few hrs, I cannot work out how to have 2 curved reflective panels on one pedastal, so it's perhaps best to stick with one & have a seperate , removeable panel for the shelter walls. Otherwise use 2 units side to side
More links to the infinity bakery