I don't think it was ice that caused my problem as I had already managed to open the door and get in. I was locked in after I had driven about 1/2 mile. If the glass had been stuck to the rubber with ice then I think would have heard the mechanism attempting to lower the window.
Actually the inside door handle was completely free i.e. I could pull it but there was no mechanical 'feel' as though it just wasn't connected to anything.