Plan C on the solar plant
Consider this option. Leave the very heavy battery bank on the porch of the second cottage, and rig/hook up the solar collector panels (already on a cart) and still use their electrical output to the battery bank. One can rig up at least 150 feet (46 meters) of solar cable to do this, and without the batteries to move around. Said another way, moving around the solar panels on a cart as part of chasing direct sun is the idea. One might expect “chasing the sun” and using direct sunlight might increase the solar collection (like making electricity from sunlight) by many levels, like 4 times more. All this assumes some electrical loss due to the long solar cable, too. And the wildcards are always the weather and time of year, also.
Right now, in May 2015, the setup is based on the 12 volt system, too. The alternatives are the 24 volt and 48 volt alternatives, also.
Now there are still other alternatives, like using a movable mirror to better focus the suns direct rays.