If you buy a compressor you will want one with at least a 1 gallon tank. You need a delivery of not only pressure but volume to blow the lines. If you use a compressor do not just apply and leave full pressure on the lines. Hit it with a series of short burst because the water will not flow out as fast as air. As you start to reduce the volume of water in the lines longer burst can be applied.
Now that said when we come home while it is still freezing at home we stop at a truck stop and blow the lines and install the antifreeze before we cross into the colder areas. In our case we can then make it home that day. You might end up in a motel one night.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles