I've hunted 20E twice for caribou and did not see a wolf on either occasion nor sign of them but I was in a fairly accessible (crowded) area. As a fair disclaimer though, my buddy thinks he seen a wolverine far off on a ridge while I was enjoying a glorious nap and another guy from work did jump a couple wolves but couldn't get a shot off on the trail in.
If you see caribou you can likely find a wolves in the area- every time I've seen wolves they were trailing caribou.
Wolverines are remarkably rare, even in areas where they are comparatively common...not worth hauling a tag. I've seen 9...only 2 within rifle range and one of those was in bayonet range...not recommended distance.
But like Stid said- it's always worth having a rifle along for the trip.
20E wolf management has been aggressive for several winters now. Winter before this one ADFG thinned out the wolf population in some of the major hunting corridors. Not many were sighted this past fall in much of 20E. Still seeing a few single prints patrolling the gravel bars along a couple of the rivers, but not many.
Have hunted Fortymile country for many consecutive years, and have noticed increasing contact with wolves the past 4 years. In both 2013 and 2014 I shot some good video of wolves while moose hunting. Even though we limit ourselves to longbows, we buy a wolf tag each year. It paid off for my partner in 2014 as he one-arrowed a beautiful black wolf mid-way through our hunt. I was able to confirm it was one I had videoed several days earlier.