In reply to ERU:
My guess is it will be pretty busy during the ice-fest but you might get lucky
we stayed here last winter
http://rjukan-hytteby.no/en/index/
Its the opposite end of town to Climb-Inn and where most of the climbing is but you'll most likely have a car so that means 5 minutes drive.
We ended up in the chalet above the restaurant which was warm and comfortable but we nearly stayed in one of the little coloured huts that sleep 4/5 and look pretty cool to me. Its also 1 minute walk to the swimming pool for a rest day or evening soak.
Not sure if 170NOK would get you much in a bar...