83 TQC brake failure- HELP

[RDG51@aol.com]

On the way to work today the brake pedal went to the floor, almost, with some
bare minimum braking left. I came home, briefly looked at the car but
couldn't get underneath to check for leaks. The brake fluid resevoir was at
min level. Earlier in the day my wife drove the car, slid on the ice and went
into a snow bank with the right side front of the car, no damage appeared to
be done, nor was there any loss of braking. The next time the car was driven
was by me. Out of the garage I noticed no change in brakes, then on going
down hill, no brakes,as described.  My question is does this sound like a
master cylinder problem or a fluid loss from a leak--presumedly due to or
coincidental to the off road experience?  Does it sound like I could drive
the car (carefully!) to get it up on a rack? I've had two opinions so far
from local resources, one is master cyl failure the other says this is rare,
something leaked in the hydraulics, probably when the car when of road.  Any
opinions advice etc is appreciated--We still have snow and I have to work
nights this weekend!