Now that that scene has been brought up, I always wondered if it would look better if that entire area was redone with something closer to what we see when Han finds Luke (not to mention that the scene above has a very "enclosed set" look to it).

Here are some alternatives...
(CGI/animated/live snowstorm footage overlayed on top of the background image, which could be desaturated or given a closer look to the overall blue-grey color timing of the Luke and Han night scenes):

Here are some alternatives to show that the cave roof would probably be darker in the shot with backgrounds similar to above (even with a snowstorm overlayed over the background image). Something else to keep in mind: it was dusk when we pull away from Han after he stuffed Luke into the Taun-Taun belly.. it wasn't full-on night yet (such as what we see in the original version of this shot). So realistically, the outside should represent dusk (regardless of whether we can actually see the sun) to at least synch up with what we see in the following shot with Han and Luke:

In the last shot, maybe the "Han on Taun-Taun coming out of Ben's ghost" could be flipped and slightly altered to look more like a regular rebel solder to show one last scout barely making it back in as the gates are in the process of closing (this could help with the sense of distance and space).

BTW, any tute links on how to create layers (in GIMP)? If it looks sloppy, it's because I used the CLONE tool to copy info from one image to another...