In reply to Phil Tucker:
If there's 4 of you, and you wanted to visit Norway, then you could easily book a cabin ("hytte") last minute. I made weekend hytte bookings with a few days notice all through last winter without problem. The only place where accommodation was harder was Rjukan. You could just book a hire car and decide the venue last minute.
Rjukan wasn't the most reliable place to visit in Norway last year. Many of the venues get limited sun, which is obviously good for ice formation, but there's limited options when the freezing levels are high. Nearly all the venues are relatively low down. Last season in Norway was a bit more like Scotland in that there were generally awesome conditions somewhere but you needed to chase conditions.
Would highly recommend Alta if you were prepared to take an extra internal flight in Norway. Good spread of grades and some really impressive routes for the grade also. Some details on my blog from last Feb. Excellent online guide here:
http://oppialta.no/index-is.htm
Oppdal and Sunndal would be a safe bet as you have a big spread of altitudes that are all accessible from the road. Something to climb whatever the conditions.