Most everyone goes to sleep at sunset, other then the couple of guards.

A couple of hours before dawn Floki Betilsen comes over "Good to see your awake. Toar, my hawk, spotted a group of trolls in a depression ahead. If they don't know we are here, they will spot us no problem in the daylight. I think it would be a good idea to take them out before morning.

You said you were some type of magic user, right? Any chance you'd have some fire spells or other useful magic. ?