Honor mode fumble: killed Marcus but Isobel died. What now?

Well. After downing Marcus round one, Jaheria oh-so kindly used ice storm and destroyed my barricade, letting the winged horrors in to kill Isobel. I survived the Inn fight and used Speak with Dead on Art to continue Halsin's storyline, but idk how to proceed to Moonrise Towers. Should I still try to ambush Karniss to get the pixie's blessing? (I don't want to carry a lantern around with all of Act 2) Will the Absolutists at Moonrise attack me since I tried to defend Isobel, but Marcus is dead? Over 800 hours in game, but first time I've ever lost Last Light and can't reload because I need those golden dice.