If the fire department refuses to send its trucks down an icy private lane that could be a serious point in your favor. But I'd try to address it before it actually happens! Keep good photo records --- I've gotten some interesting reactions via a polite discussion with Deputy fire chief or local codes/fire inspector --try what works in your community.
It may well be the duty of the contiguous property owners to maintain safe passage on that private driveway.
Many towns have adopted some form of property maintenance code .Can be used to drive a recalcitrant owner nuts IF somebody in City Hall digs in.
Your neighbors insurance is likely to go thru the cost roof or get dropped IF her insurance company finds out the place is uninhabited --if you can think of ways to alert her carrier--so be it.
Is you neighbor current on her local taxes --often a public record ---empty properties that go tax delinquent for long times can be big problem for town to collect....
Ditto, check water --in my town, if the water were to be cut off the CO gets lifted as well and that can trigger entire building must be brought up to new code --deadly if enforced against many an older building. Water flow in basement is probably inconsistent with current codes.
A few squirrels running in and out may not get any real attention --but if you mean rats and feral animals and have pictures of same it might be different. And if young kids or thugs have made use of property for unsafe or illegal purposes that might get attention in some places.
Hey, picket lines with informational signs and pictures in places where it is lawful to picket ?