If you are planning to use a solar system for an off-grid cabin, you definitely won’t have to install the same size system as you would for an average-sized home. Cabins tend to be on the smaller size with a lower number of electronics to power on a consistent basis.
Also, if you have alternative heating sources (for example, a wood stove), then you won’t need to install a system that can run electric heat comfortably.
Determine if you plan to use only solar panels or you will use battery backup storage power to run the electronics of the cabin. However, a small to average size cabin will require at least three moderated-size solar panels to run electronics comfortably but remember! You can only use solar panels during the daylight hours so a backup system is imperative.