Kia Sedona brake failure in winter

I recently had a problem with my 2015 Kia
Sedona. Twice in the space of an hour my
brakes failed. I was going at low speed. There
was snow around but no ice on the road.
Suddenly there was a loud grinding noise and
the brakes did not work when I tried to slow
down. The second time I was unable to stop
at an intersection and I ran right through it.
Thankfully there was no one around or I could
have caused a fatal accident. I have snow
tires on the car. The car did not skid as on an
icy road. I did not feel any vibration as I
apparently would if the ABS was activated.
The brake just failed to stop the car when I
pushed down on it. After a few minutes it
started working normally again and has done
ever since. My garage and the Kia dealership
both test drove the car and could not
reproduce the problem. The brakes were
apparently in perfect condition so they said
there was nothing wrong. My garage said it
was the ABS system that was working the
way it is designed to work. The bottom line is
that the brakes failed albeit briefly and I was
extremely lucky not to have caused a fatal
accident. This happened once before in my
2012 Sedona. I am now nervous. It was only 3
times over a period of about 7 years but once
was too many times. Anyone have a similar
problem? Any ideas what the problem is and if
it can be fixed?