Iggysbabysitter is right -- if your freezer has a significant amount of empty space, fill some of the space up with milk jugs or 2-liter bottles, or even plastic zip bags, filled 3/4 full with water. Don't fill them all the way, because you must leave space for the water to expand as it freezes.
When we had a hurricane knock our power out for a week, we were glad we had prepared. We didn't have a lot of empty space in our chest freezer (the same size as the one we have now), but we filled what space we had with gallon-size freezer ziplocs of water. We then wrapped the freezer with blankets (you have to leave the places where it draws air in and puts out heat uncovered -- the heat is often emanated from the back of the freezer, even if the coils are not visible). That freezer had a "deep freeze" setting which was even colder than its regular setting, meant to freeze things quickly. We set it to deep freeze, and turned off the breakers to everything but the freezer (we had already emptied the fridge).
When we returned, the people in the apartment complex started having community cookouts using the food that was thawing in their freezers, so it wouldn't go to waste. We figured maybe we'd have something to contribute the second night, but we ended up having to take things out of the freezer to thaw them because nothing was thawing in the freezer. And it was warm in the house -- September on the Gulf coast.
By the end of the week, when our power was restored, everything in the freezer was still as hard as a rock. Several years later, the freezer finally gave up the ghost. It was pretty old.
Dirty Harry, I am so jealous! Four freezers? Boy, the sales I could take advantage of.....!