Use great care in the review of the electrical design of the solar powered cabin you may be considering.
I might even suggest a QUALIFIED home inspector. A PE would be my choice if you feel uncomfortable.
Click on the picture and notice the water storage tank and the concrete block vented battery enclosure in a dedicated utilities room.
There are a number of considerations for winter and summer use.
I have always had hot showers for 25 years irregardless of the rest of the planet. 3500 gallons of clean water in the basement.
Plumbing design is more than important!
Don't forget the trout!!!!
How about a 720 square foot code built toy box???
Solar powered lighting!