The short answer is this, you can buy insurance. The real answer is the same as everyone that has a second home already knows. I am sure you are already taking the sensible precautions, after that, there is nothing more you can do. Ours was broken into last winter. There was nothing worth taking so i am sure out of spite they knocked the thermostat of the wall. So we replaced the thermostat and fixed the front door they had broken down. Life goes on. P.S. - our yard is fully lighted, I'm sure they thought about that for about 1.3 seconds before they kicked the front door in.