The best thing you can do for peace-of-mind is to leave the heat on at about 50F or so - but that is sometimes tricky with mobile homes as there are often pipes on outside walls that can still freeze if the place is poorly insulated.

You will have to drain all the fresh-water systems including the hot-water tank, and back-fill with RV antifreeze. Pour that in your toilet and all your drains (don't forget the washer drain if you have one). You do not have to fill the hot-water tank with RV antifreeze - just as much of the pipes as you can get to. There should be main drains for your fresh-water system somewhere - your manual will tell you where. And if you have hard-connected water-service, you will have to put heat-trace on the water service to prevent that from freezing.

When you get back, just flush out the antifreeze (it is sweet-tasting but non-toxic) and leave the heat-trace in place - that you can use over and over.

Good luck with it.