(Spoiler for act 2) should I restart?

I'm playing through an honor mode run and just lost the fight at the last light inn. Isobel triggered like 7 attacks of opportunity in a row and got herself killed before the first round was even over. Now the whole Inn is dead.

I have never had this happen before and I am 100% positive there is many ways forward, but my question is if it is going to be exceedingly difficult to take the good path of the story from here? In every run I've had so far, the Harpers help fight at moonrise towers, and I don't think I can handle that fight without them.

Is there a change to the fight if the Harpers aren't there to help? Or is there another easier way to get in and kill Ketheric without doing it? I will not consider any suggestions that involve siding with the Absolute. I just want to know if it's feasible or if I should just save myself the time and restart now.