In reply to petre:
There is plenty ice scattered around what you might call Lillehammer Valley stretching all the way up beyond Ringebu , but it's not concentrated like at Rjukan, so expect to drive, trudge or ski a little, there is some relatively road side, but you need to consider descent too.
Define cheap... cabin hire is cheap (under £100/night), but you're late to the party and most will be booked up. Who'd go to the alps to ski, currently Hafjell has 70cm snow on the hill, 40cm valley bottom. Avoid the 3 week window over half term as your accommodation options will be even less. For example
https://www.stugor.biz/norge/lillehammer.htm#/na/4
Sjusjøen, above lillehammer with masses of cabins, no doorstep ice but arguably one of best nordic ski trail networks in the world.
The club did have a pdf to download (years ago), now they appear to sell it.. https://www.lillehammerklatreklubb.no/Isklatring but the link didn't work. I can't find the old pdf, but somebody else here might be able to send you it.
Post edited at 13:59