Do dungeons and outside forts etc. actually respawn? If so, how long after?
Also does anyone know if ore veins "respawn" ?
And how long does it take for dead wolves bodies to disappear, if ever?

I feel I should know, but I just dont, and was wondering if anyone knew?

Fallout and Oblivion seemed to use 72 in game hours to respawn dungeons etc so i guess its safe to assume the same applies here.

Yes, certain dunngeons and forts do respawn. I think it takes 720 ingame hours.
I'm sure I saw someone on here earlier say ore veins don't respawn (but don't trust me on that).
No idea about the third question.

If i'm not mistaken it's 1 month game time.

Keep well rested on and it'll go by a bit faster.

I don't think they reset because on the world map when you move the cursor over a cave etc it says cleared under the name of the cave/mine/ruin

Yes they do... even though it says "cleared." The strategy guide says, "most dungeons reapawn anywhere from 3 days to one month game time." So, there you go.

Looks like my character will be taking lots of naps