With the lda glacier you can buy a day pass and then at the end of the ski day if you shape the park you can get the following days pass for free and continue doing that. So it is possible to ski on the cheap. For accommodation, I know there was a thread of a group of people with an apartment looking for others to stay with try using the search bar or google with Newschoolers.com in the search to find it.
Having not done it myself i can only speculate. It doesn't seem that it is done in a formal way and so its a case of hanging round the shapers hut around lift closing time and speaking to somebody that looks like they're in charge about it. I do know that it isn't a rumour and that there are number of members on here who claim to have done it. If you search for the threads on summer skiing in lda you should be able to find them and message them about it for more details.