I believe that guy lives up in a little spur at the NE edge of the map, and won't come down if you don't wake him up. So my first advice would be to try "a knife stealth grenade thing" and, even if you have to fight, you may be able to leave him resting (knife fighting is silent or nearly so). Possibly get seen deliberately by the rathounds and draw aggro up away that SE corner so the fight is even farther away from his home.
If you have to fight him, I agree with harperfan7. Flashbangs, bear traps, tasers, also molotovs. Caltrops can also work, although may be hazardous to you as well. They may be stupid enough to walk into bear traps as long as that's the shortest path to you, even if there is another way around, not sure. They're bugs, not too bright, so I think it's likely. I usually relied on molotovs and flame resistant gear myself.