A couple "quick" thoughts/questions...
Is this thread to include specific mechanics of language that we remember from the series, as well as derived information logically deduced from what we have read? If so, just wanted to add that indeed, Go-Backs did have a more refined vocabulary for snow, at least compared to the Wolfriders. Not only did they have words for snow the wolfriders didnt (wolfriders referred to it as "whitecold" if I remember, and something like "deathsleep" or something for the season of winter), but used descriptors of snow to describe other things, such as "crustings" for the passage of time.
I also wanted to mention a thought: the basic language is "primal", in that the Trolls, Elves, and Preservers all use the same language throughout the ages, rooted from what was used onboard the shell/"Palace" before becoming marooned on Abode. The Trolls would have little use for the "name-Ability/root" subset of the language as it has magical/spiritual meaning and Trolls are more rooted in function.
Further, it seems to me that while the base language is fixed and the same between all races and tribes, the difference in the range and use of vocabulary between groups could be expressed as dialectal differences, much like how many places in the world speak English, and each can usually communicate fluently with the others, but British english, Austrailian english, American english, and even subgroups of these all have unique ways of expressing similar concepts.
Anyway, what Im getting at is that the Sun Villagers might speak more of a "High Elven", while the Wolfriders might speak a more primal "Low Elven", reinforcing the status differences that some characters impose on the wolfriders throughout the series. This would follow for more that just because they dont send, but that they have an Elder among them that remembers quite a bit of the earlier times, while the Wolfriders have few that were even close to a tenth as old as Savah.
One other note: the elven laguage is nearly impossible for humans to pick up, especially as compared to how easy Elves can pick up human language.