While I certainly believe it is possible, I think it is extremely hard.  And starting with less than three heroes or ensuring you have low starting threat makes it hard as well.  My reason is the threat generated from having 12 cards in play BEFORE you turn over 4 more just to start the encounter phase.  (3 baddies x 4 players and then an opening draw of 1 encounter x 4 players)

So you will have to generate enough willpower with your starting heroes (and whatever cards you can purchase for the measly 3 resources you start the game with) to overcome 12+ enemies.  

In all likelihood you are going to encounter a +12 threat after resolving the questing phase.   And if you somehow reduce that, then it means you dedicated everybody you have to questing…so you have ZERO heroes left to actualy defend against or kill the 12+ enemies who are now going to engage you because you just took the +12 threat.

If you let the snaga scouts in undefended since they only do 1 dmg each. Still takes some luck and a group of heroes who´ll be bleeding afterwards. Sacrifice some allies to the wargs and they will be mixed back into the encounter deck so you can handle them later. It´s a tough start and requires some tough sacrifices for the best chance of survival

PS: never beat it in 4-player myself

I guess Legolas/Brand with the new "Hands Upon the Bow" card makes it much easier: You can shoot a Wolf in the staging area in turn one!

Same story 4 players no chance to win. But is possible of course but really difficult. I dont have so much chance to play with 4 players unfortunally.

 It is possible to win this quest with 4 players, but the decks have to be designed to be prepared to it.

In my play group we beated it with the following heroes:

A- Beorn, Hama, Legolas;
B- Boromir, Glóin, Glorfindel (spirit);
C- Brand Son of Bain, Thalin, Dain Ironfoot;
D- Bifur, Eowyn, Eleanor

You can see the results in javascript:void(0);/*1348685183840*/