Turn off main water supply. That solves a lot of potential problems even if gone for a few days. Hoses to washing machines do spring leaks. Get a freeze alarm that will call your cell phone. Not expensive. Security system is good idea with locks and motion. Install motion lights outside. I installed internet cameras so I can view critical areas for problems. Notify neighbors. Don't let newspaper or mail accumulate. I have light on. Heat at 55. For me 50 was too cool and got some moisture. 55 was perfect. Still a lot cheaper than when there.