The rationale behind this project is to create a mobile home that is capable of getting to remote areas and staying there for months at a time. This necessitates the ability to:
accommodate temperature extremes in relative comfort
provide sleeping, cooking and "lounging" facilities
provide refrigeration for food and drink
produce our own power
provide enough storage to carry food, water, fuel, gas bottles, recovery gear etc.
keep clean i.e. have a shower with hot water
accommodate the by-products of eating i.e.toilet facilities
store waste products such as rubbish, gray water and black water.
Some compromises are necessary - a huge off-road vehicle wouldn't be able to get into many places. If money were no object, the design would be different but it is and it isn't.  ;-)