What your referring to is the angle of attack with regard to the drveway angle problem.
As I mentioned before the majority of the snow casters available are too light in front to do any good. The BCS 835 2 wheel tractor wiith the Berta 32 inch snow casterf is more than enough tractor for what you want.
You can always buy snow chains for the BCS 835 and wheel weights and you will have lots of digging power and traction.
A track drive snowcaster will have issues with ice and traction unless you have a heavy honda or Yamaha or studded tracks or studded tires on the snow caster.
If your little driveway is the only issue all you need is a 12 horse tractor, snow chains and a 2 stage snow blower for the tractor.
You should be able to get an off season mowing tractor bargain from John Deere and a snow blower attachment with chains for much less money than dealing with a dedicated snow blower that may cost you more than twice the cost of a 12-18 horsepower lawn tractor with the attachments.