I have been hunting for a solution. There are a surprising number of companies that sell cables or mats that go inside the asphalt or concrete, and you can have the cables installed after the fact by cutting trenches in the surface. For 600 feet that sounds expensive. I suspect that just a melting cable just under the edge of the pavement would do the job. This is advertised as 12 watts per foot. There is a 240 VAC 428' length listed, which would get me to the worst part. This would get most of the way down the driveway; a heavy gauge 240 VAC extension cord would get the rest of the way down perhaps in some waterproof conduit. This is a bit of money, but it would end plowing, and greatly enhance house value.
According to Google Earth a path along the driveway from garage to base is about 879 feet.
As the crow flies, 659 feet:
Since I will need two sections, I could use one 428' segment to the big turn along the pavement, and a 240VAC line from garage to the big turn, and the 428 heat cable to the base, which is 424'.