It was very cool! I think if we hadn't been in the middle of nowhere by ourselves with a tiny scary rocky track that you could only creep along in a 4x4 to get to the base I might not have been such a chicken. I have no idea how you would get away with any haste if it went boom!
Hekla's the one that does tend to only give a small warning between first tremors and an eruption, so perhaps it was wise not to hang around! As far as the snow goes, looking at the first webcam I mentioned, they're having a bit of a blizzard at the moment! <adds visiting Iceland to list of things to do>
Don't worry eurochick, we survived ours despite threats of imminent eruptions I think the worst that would happen is that you could get stuck just on the other side of it on the ring road and have to drive all the way back round Iceland to get back to the airport! (We also had threats of a glacial flood breaking through and washing away the ring road).
My biggest tip is to get gravel protection insurance for your hire car. We picked up a chip on our last day (ironically on the ring rd which considering the rds we had been on....) and they would have charged us if we hadn't got the insurance.
'Cut and Paste' is my friend when it comes to long Icelandic names! Is that bridge near Katla? I did know there was a bridge there that got destroyed a few years ago. There's a bit here about it, under the heading '2011 eruption.'
OYBBK I think the amount of snow is very variable. I went there many years ago and there was heavy snow all week but the week before there had been none. The next time I went there had been heavy snow the week before it had all disappeared within a few days and we didn't see any.