In reply to gethin_allen:
Same... and why I was using the Italian hitch when rope frozen
Not icy but wet ropes, I deal with on a regular basis and friction is reduced that way making abseil either free fall or grab and little in-between. The rope abusing Italian seems to be far more even behaviour wet or dry, so a good plan B if having problems in wet.
I use ATC and use it backwards (i.e. don't use the grooves for the braking side) when abseil ropes dry and correct way round with the grooves on braking side when wet rope. With a petzl stop just ordinary when rope is dry and clipped in petzl Freino extra friction when wet.
If abseil with Grigri, petzl actually recommend using a Freino, so if that's what you were using consider getting one