Okay, assuming that they will involve the works of R.A. Salvatore somehow (and how can they not dip into that cash cow?)
As Umbran says, it's pretty clear they're not going that route, largely because the script was written before the settlement (and therefore before they were able to use the FR setting/names/plots).
However, for casting an "Icewind Dale" movie, I'd look to "Thor 2: The Dark World", which basically did it:
Drizzt = Algrim (Adewale Akinnuoye-Agbaje)
Wulfgar = Thor (Chris Hemsworth)
Bruenor = Volstagg (Ray Stevenson)
Cattie-Brie = Sif (Jaimie Alexander)
Though I'm not sure who they'd cast as Regis or Entreri, as they don't have clear analogues in that film.
I'd also be inclined to look to that movie for the depiction of Drow, as that could potentially be problematic if and when the Dark Elf trilogy is tackled.