About a week ago I slid into a very small ditch in the snow. I was making a left turn when my right wheel fell in. I was able to continue on immediately after it happened. There was not a significant amount of impact, however, it screwed up my wheel alignment and knocked out the power to my rear wheels. So it's as if I am driving a 2 wheel drive car. The "Check VSA Assist" light comes on after about 5 miles of driving now.

Any ideas what this could mean? Especially considering how little impact there was.

 

I would guess the impact was greater than you thought. I think you need to bring the car to a shop they can inspect the underside on a lift.

 

Agreed on this. Maybe the wheel side into a ditch and caught on the wiring for the wheel speed sensor. Maybe it damaged your axle. Could be a number of things...definitely get a physical inspection.