Do you have any advice for potential travellers?
If you've never skied before, do some exercises and try to improve your balance before coming out. Cross-country skiing is tiring, much more so if you fall a lot.
I went in early February and the area was fairly quiet, snow was good and there was plenty of daylight. Mid-February is busy with Danish families on half-term and then the main season continues into April but Norway almost never feels crowded.
Although it's primarily a skiing holiday the area is good for many winter sports including ice climbing and snow shoeing. If you struggle with the skiing don't be afraid to give yourself a break and try the snowshoes - or 'freedom shoes' as I now call them ! They will take you anywhere and are not at all hard to use.
Kvitavatn is a family resort rather than a 'live-it-up' place with lots of night life and apres-ski. If you want alcohol then bring it with you (there's a supermarket in Rjukan and a free skibus from the lodge) but my advice is to enjoy the hills and forget the booze most of the time. A hip flask is the best bet !
Arrival at the resort isn't until about 1.00 am after a 3 hour coach trip from Oslo Gardemoen. There is food on arrival but it may be good to take something with you on the coach.