So I've been thinking alot about this, and it may be the wrong answer, but it seems to me that if something is not single combat you should not use the single combat rules and if something is not battle, you should not use the battle rules.
Now, depending on how the wolves work it could be single combat. Think of the pack as a swarm from D&D, instead of individual wolves. I don't see it working as battle. While I could see a single warrior holding a stairwell against an invading army as battle, I'm not sure a stand against wolves works. Also some of the move options in battle suggest that it should not involve a single combatant(like a single combatant takes harm personally) however that could just be given as a free spend I suppose.
I would run this situation though as a series of standard moves. Show evidence of what's coming through the howling of the wolf pack. Most likely this will cause them to look around, triggering Take stock. If they fail, wolves attack, and inflict harm as established. If succeeds, they can describe their actions which will trigger either leap into action or undertake great labor depending on if they attack or try something else. I they fail, more harm or possibly captured, their prize weapon broken, or something similar. Continue on this vein until the scene is resolved, most likely in the Troll killer's death, but perhaps (s)he prevails.
It does bring up something one of the guys in my group has a problem with. There is not standard, reactive option similar to do something under fire. I feel that "leap into action" and "Undertake Great labor" will work for this, he does not. We've yet to put it to the test but in my head I see it working, hence my view of the scene above.