Solar/wind is a good combination and the system typically lasts at least 20 years if the upkeep is done. Solar panels are guaranteed for 20 years and the bearings in a windmill will last forever if they are kept lubricated. The only things you would have to worry about are periods of low wind with cloudy days, acts of God, and battery upkeep. The batteries will usually last 15-20 years as well. You also have to severely limit your use of power to make this system work most of the time. Being "off grid" can be satisfying, but having the power lines hooked up when you need them is good for piece of mind.
