Locked out of Frostmarch (Softlock?)

I usually play in coop with a friend however as is pretty well known at this point signal fires (fast travel points) are bugged in coop and cant be unlocked by the non-host player.

So when reaching frostmarch i already asked myself the question "how am i getting back here in singleplayer if i cant activate the signal" and i guess the simple answer seems to be...i don't?

Is there any way for me to get back into frostmarch without having to fast travel or am i just fully locked out of that place in singleplayer now?