So tundra Dalish (specifically Arctic tundra). Which could go completely wrong, because I’m guessing based on what little i know of such terrain.
South of the Korcari Wilds are the lands the Chasind call “the Sunless Lands” (which in elvhen would probably become something like “Place where the sun does not emerge” or something.
Elgara'an Tel’ena?Elgara’tel’ena’an? Probably very wrong, but elvhen has no grammar so idk how to actually write that (seriously Bioware.)). Anyway, the Sunless Lands are an expanse of tundra. While it may be unlikely Dalish would go that far south, who knows? It’s unknown to modern Thedas so it keeps them safe from Andrastian society.
Tundra clans not being hunted by templars and probably rarely encountering human settlements would probably be much more stationary than Dalish from other environments. How safe they are depends on how they get along with their Chasind neighbours, they may ignore each other, be at war or trade. idk.
They would likely migrate however, possibly North into the Korcari Wilds come winter.
Living in a frozen waste which is very likely to kill them they would likely look favourably at their fire-related Deities, which makes Elgar’nan or Sylaise the candidates. probably Sylaise, being the god of practical fire while Elgar’nan is more the destructive kind. Elgar’nan is associated with night (having created it by throwing down the Sun) but since nights on an ice-desert likely mean “a few hours to freeze to death” I imagine his position as a dangerous deity is heightened. Not that the day is much better because hey, snow blindness.
I can imagine them living along the coastlines, with the sea as their primary food source - which religiously would mean that again Mythal becomes a very important deity, being the goddess who walked out of the first seas (sea goddess, mother, protector, provider). Andruil becomes a goddess of fishing along with hunting, and is associated with marine predators along with hares and hawks.
Having to survive with what little resources are available to them (meaning they have to be very inventive with what they have) probably means craft gods like June and Sylaise are important.
Living in such difficult and dangerous environments with no danger from templars I can actually imagine them having a higher esteem for mages and magic than even other Dalish because let’s face it when your survival rests on making the most out of every resource you have you damn well use it. So magic is used pretty much on a daily basis. Falon’Din is likely hailed more for his status as God of Fortune, and revered for his ties to the Fade (likely making him the god associated with dreams and magic itself). Dirthamen would also be favourably regarded, but likely to a slightly lesser extent.
Ghilan’nain and Dirthamen are likely viewed as gods of navigation and secrets/discovering secrets. Rather than his usual reputation as a god of academic/arcane knowledge, Dirthamen’s secrets are likely more of the “where is the danger”, “where is safety” kind of secrets.
How would they deal with their dead? Since the point is to return them to the land… Burying them in the North when they migrate for winter? I suppose provided the death rates aren’t too high they could preserve the bodies for a bit. idk.
Arctic halla are enormous (compared to the common halla). Tall and heavily built with thick poofy/shaggy white fur to survive the cold. With the Tundra Dalish only needing to move on in Winter/when food is getting scarce, Arctic halla probably serve more as the occasional mounts for scouts/hunters and providers of milk - I wonder if you can shear them for their fur? (Yes I know they’re deer and that’s a silly idea). That said they are still not cattle, halla remain friends and kin, and are greatly respected for the sustenance they provide and as guides (a halla can spot a crevasse or an oncoming blizzard well before their elven companions).
Thanks to the apparent magical adaptiveness of elves, tundra elves are far hairier than other elves. Their body hair is thicker and they have even been known to sport beards.